Buffer zones and international rivalry: internal and external geographic separation mechanisms

Abstract

The recent Russian invasion of Ukraine has led many commentators to remark that ‘geopolitics is back’. And with geopolitics, the interest in buffer zones is back as well. Yet, International Relations scholarship on buffer zones is confusing and outdated. Scholars disagree on the definition of buffer zones and whether such zones are a vestige of the great power politics of the past or a continuous phenomenon. In this article, we take three steps to reconceptualize buffer zones and their role in international relations. First, we clarify the conceptual confusion by advancing a new definition differentiating between nominal and active buffer zones. Second, we make the case that buffer states and internal buffer zones (i.e., geographic borderlands located within states in rivalry, adjacent to the international borders between the two rivals) share much in common and therefore should be analysed in tandem. Third, we offer a typology of buffer zones with short case-studies based on the dyadic relations of rival states vis-à-vis buffer zones between them. Our goal is to provide a new analytical framework that can serve as a base for a robust research agenda on the role of buffer zones in regional and international stability and security.

Full text

Buffer zones and international rivalry:
internal and external geographic
separation mechanisms
BOAZ ATZILI AND MIN JUNG KIM*
International Aairs 99:  () –; : ./ia/iiad
© The Author(s) . Published by Oxford University Press on behalf of The Royal Institute of International Aairs. All rights
reserved. For permissions, please e-mail: journals.permissions@oup.com
The Russian invasion of Ukraine in  has led many commentators to remark
that ‘geopolitics is back’. And with geopolitics, the interest in ‘buer zones’ is
back as well. There has been a lively debate about whether or not Ukraine or
some segment of its territory should—or could—become an eective buer
between Russia and NATO allies since the Russian annexation of Crimea in .
Conventional wisdom holds that buers were important in maintaining peace and
security in interstate rivalry in the past. Yet scholarship disagrees on the definition,
function and relevance of buer zones in the current era.
In order to comprehend the role of buer zones in conflict mitigation, one
needs a clear understanding of what buer zones are, and when and how they
might aect interstate relations and security dynamics. Following a brief survey
of the literature on buer zones, we attempt to accomplish this task through four
steps. First, we discuss the scope of the phenomenon, arguing that the buering
logic for conflict mitigation can only work in a dyadic context involving two rival
states, and not through buers unilaterally imposed by one state. We also argue for
the inclusion of both buer states and what we term ‘internal buer zones’ within
the scope of the idea. Such internal buers are geographic borderlands located
within states in rivalry and are adjacent to the international borders between the
two rivals. Second, we dierentiate between active and nominal buer zones and
explore the mechanisms through which active buer zones may mitigate conflict
between rival states. Third, we construct a typology of buer zones based on
dyadic engagement of rival states within the buer territory. In addition to
nominal buer zones, we introduce three forms of active buer zones: zones of
neglect, contestation and management. We follow with a few short illustrative
* The authors would like to thank participants in the April  Conference on International Borders in a
Globalizing World at the Perry World House in the University of Pennsylvania, the April  Political
Violence and Security Workshop at American University, and the  Annual Meetings of the International
Studies Association. We are particularly grateful to Martin Bayly, Arie Kacowicz, Miles Kahler, Michael
Kenwick, Sahil Mathur, Dave Ohls, Jordan Tama, Anna Zhang, and three anonymous reviewers for their
constructive feedback and suggestions to improve this article.
 Roy Allison, ‘Russia, Ukraine and state survival through neutrality’, International Aairs : , , pp. –
; John Mearsheimer, ‘Don’t arm Ukraine’, New York Times,  Feb. ; Daniel Drezner, ‘Why Ukraine
cannot be a buer state’, Washington Post,  Feb. ; Brandon Valeriano, ‘Yes, Ukraine is still in crisis: would
becoming a “buer state” help?’, Washington Post,  July ; Audrey Kurth Cronin, ‘Could Ukraine become
neutral, like Switzerland? Five things to know’, Washington Post,  March .

Boaz Atzili and Min Jung Kim

International Aairs 99: 2, 2023
cases to provide a more grounded picture of how varying patterns of interstate
engagement produce these three types of active buer zones. We conclude by
oering some preliminary conjectures and suggesting avenues for future research.
This article aims to contribute to the conceptualization and understanding of
buer zones and set an agenda for more coherent and systematic research on the
role of buers in interstate relations, conflict and peace.
Buffer zones in International Relations scholarship
Buer zones are a grey area in both geographic and disciplinary senses. These
zones lie between domestic and international boundaries. In disciplinary terms,
they straddle the realms of International Relations (IR), comparative politics,
political geography and history. While a large body of scholarship is relevant to
understanding the dynamics of buer zones, the literature that directly addresses
these topics has been limited and disjointed.
In IR literature, the study of intrastate territorial peace and conflict is extensive.
Likewise, intrastate territorial conflict, often in the shape of separatism, has gained
much attention among comparativists. A growing body of work focuses on the
role of interstate relations in cross-border security and political dynamics, such as
conflict spillover, external interventions and state-building. Yet most of these
writings do not highlight the dynamics of marginal territories in the international
system or borderlands in the context of interstate rivalry, critical in understanding
buer dynamics. While critical geographers and historians explore the dynamics
of borderlands, they seldom consider the interactive processes between borderlands
and interstate relations—a process at the heart of the idea of buer zones.
A small body of literature focuses more directly on buer zones. These writings,
in a significant way, help us understand both the origins and the consequences of
 See e.g. Gary Goertz and Paul F. Diehl, Territorial changes and international conflict (New York: Routledge, );
Paul Huth, Standing your ground: territorial disputes and international conflict (Ann Arbor, MI: University of Michi-
gan Press, ); Paul R. Hensel and Sara McLaughlin Mitchell, ‘From territorial claims to identity claims: the
Issue Correlates of War (ICOW) project’, Conflict Management and Peace Science : , , pp. –; Beth A.
Simmons, ‘Border rules’, International Studies Review : , , pp. –.
 Barbara F. Walter, ‘Explaining the intractability of territorial conflict’, International Studies Review : , ,
pp. –; Monica Toft, The geography of ethnic violence: identity, interests, and the indivisibility of territory (Prince-
ton, NJ: Princeton University Press, ); Douglas M. Gibler, ‘Outside-in: the eects of external threat on
state centralization’, Journal of Conflict Resolution : , , pp. –.
 Idean Salehyan, Rebels without borders: transnational insurgencies in world politics (Ithaca, NY: Cornell University
Press, ).
 Jerey Pickering and Emizet F. Kisangani, ‘The international military intervention dataset: an updated
resource for conflict scholars’, Journal of Peace Research : , , pp. –; David E. Cunningham,
‘Preventing civil war: how the potential for international intervention can deter conflict onset’, World Politics
: , , pp. –.
 Melissa Lee, Crippling Leviathan: how foreign subversion weakens the state (Ithaca, NY: Cornell University Press,
); Enze Han, Asymmetrical neighbours: borderland state building between China and Southeast Asia (New York:
Oxford University Press, ).
 Chris Rumford, ‘“Seeing like a border’”: towards multiperspectivalism’, in Chris Rumford, ed., Cosmopoli-
tan borders (London: Palgrave Macmillan, ), pp. –; Corey Johnson, Reece Jones, Anssi Paasi, Alison
Mountz and Chris Rumform, ‘Interventions on rethinking “the border” in border studies’, Political Geography
: , , pp. –.
 Peter Sahlins, Boundaries: the making of France and Spain in the Pyrenees (Berkeley, CA: University of California
Press, ).

Buer zones and international rivalry

International Aairs 99: 2, 2023
the phenomenon. Yet the scholarly discussion of buer zones has been challenged
by several key disagreements in respect of definitions and scope.
First, the existing literature disagrees on which conceptual elements constitute
a buer. Scholars employ various criteria to define buers, as shown in table .
These definitions are not necessarily wrong, but the lack of consensus often results
in measurement issues. We attempt to clarify this confusion below by dierenti-
ating between what we call active and nominal buer zones.
Source Definitions Criteria
Fazal States geographically located between
two other states engaged in a rivalry,
unless the rivals are separated by an
ocean.
Location;
relative power
Menon and
Snyder
States or zones lying between two
more powerful rival states but not
dominated by or allied with any of
them
Location; relative
power; foreign policy
orientation
Partem Small independent states between two
larger states
Location; relative
power; foreign policy
orientation
Chay and Ross States situated between conflicting
spheres of influence, whose primary
function is to separate the conflicting
sides and thus reduce the likelihood of
physical (military) contact
Location; function
Spykman A relatively weak state, geographically
located between two strong states
Location; relative
power
Buzan and
Wæver
A state or mini-complex within a
security complex, whose role is to
separate rival powers
Function
Mathisen A small independent state lying
between two larger, usually rival,
states (or blocks of states)
Location; relative
power; foreign policy
orientation
Sources: Tanisha Fazal, State death: the politics and geography of conquest, occupation, and annexation (Princ-
eton: Princeton University Press, ); Rajan Menon and Jack Snyder, ‘Buer zones: anachro-
nism, power vacuum, or confidence builder?’, Review of International Studies : , , pp. –;
Michael Greenfield Partem, ‘The buer system in international relations,’ Journal of Conflict Resolu-
tion : , , pp. –; John Chay and Thomas E. Ross, Buer states in world politics (Boulder,
CO: Westview, ); Barry Buzan and Ole Wæver, Regions and powers: the structure of international
security (Cambridge: Cambridge University Press, ); Trygve Mathisen, ‘Buer states’, in Trygve
Mathisen, The functions of small states in the strategies of the great powers (Oslo: Universitetsforlaget, ),
pp. –.
Table 1: Definitions of buer states in the existing research

Boaz Atzili and Min Jung Kim

International Aairs 99: 2, 2023
Second, with few exceptions, scholars tend to focus on buer states and exclude
the dynamics of buer zones at the subnational level (what we term ‘internal
buer zones’). Yet, as we will discuss below, there is a significant analytical advan-
tage in studying buer states and internal buer zones within one theoretical
framework. Both forms of buers may play a similar role in conflict mitigation
in interstate rivalry.
Third, scholars disagree on whether buer zones are exclusive to situations
involving dyadic rivalries or could also be imposed unilaterally by one state to
mitigate external security threats. Fazal, who has conducted the most comprehen-
sive empirical study of buer states to date, defines them as ‘states that lie between
two other states engaged in rivalry’. Menon and Snyder agree with the defini-
tion but add that the buers should not be dominated by either rival. Yet others
consider that buer zones could be a product of unilateral action by one state
(or actor). For instance, the US military defines a buer zone as ‘a defined area
controlled by a peace operations force . . . formed to create an area of separation
between disputing or belligerent forces and reduce the risk of renewed conflict’.
Academic works on southern Lebanon and northern Syria treat them as buer
zones created by Israel and Turkey respectively. In the next section we argue that
buer dynamics cannot be reduced to the actions of one actor, and we fall on the
side of the dyadic argument.
We believe that these dierent criteria and definitions do not stem from funda-
mental disagreements. Instead, they emanate from confusion and conflation of the
geopolitical location of weak states and borderlands in the context of interstate
rivalries, their foreign policy positions and the functions of buer states. Clari-
fying these dierences and the implicit assumptions built into the definition will
enable us to advance our understanding of buer zones and their role in world
politics.
Buffer zones: denition, function and scope
Denitions
In this section, we provide several key definitions foundational to understanding
the role of buer zones in interstate security dynamics. In the following sections
we expand the context and logic of these definitions. Our conceptual framework
departs from the earlier work by (a) dierentiating between the location and the
function of territories (active and nominal buers) and (b) including both buer
states and subnational buer territories. We exclude other phenomena that share
 See e.g. Lionel Beehner and Gustav Meibauer, ‘The futility of buer zones in international politics’, Orbis :
, , pp. –.
 Fazal, State death, p. .
 Menon and Snyder, ‘Buer zones’.
 Cited in Beehner and Meibauer, ‘The futility of buer zones’, p. .
 Avraham Sela, ‘Civil society, the military, and national security: the case of Israel’s security zone in south
Lebanon’, Israel Studies : , , pp. –.
 Beehner and Meibauer, ‘The futility of buer zones’.

Buer zones and international rivalry

International Aairs 99: 2, 2023
some features with buer zones but do not operate within the context of inter-
state rivalry’s conflict mitigation.
• Buer zones: Broadly, a buer zones is a territory—a weak state or borderland—
located between two significantly stronger rival states that share land borders with the buer
zone. This is a dyadic geopolitical definition based on the territory’s location
vis-à-vis its neighbouring rival states. As discussed above, scholars disagree on
whether it is only about the geographic location of the territory or also its
function in mitigating conflict. We argue that both geopolitical location and
conflict-mitigating function should be included in conceptualizing buer zones.
A certain geopolitical position of territory, however, may not be sucient
to mitigate a conflict between stronger neighbours in rivalry. That is, not all
geographic buer zones actually function as buers between rivals. To avoid
such confusion, we dierentiate between active and nominal buer zones.
• Active buer zones: Territories (weak states or borderlands) geographically located between
two stronger rival states, which play a part in conflict mitigation between the two rivals.
We elaborate below on this conflict-mitigating function, which is key to under-
standing the dynamics of buer zones.
• Nominal buer zones: Territories (weak states or borderlands) geographically located
between two stronger rival states that do not actually mitigate conflict between these
two rivals. A nominal buer could potentially serve as an active buer, yet in
practice, the rivalry dynamics within the buer zone do not allow for such a
role. Nominal buers are more likely to exist in situations where one of the rival
states dominates the buer zone and exerts disproportional influence over it.
• Buer states: These are relatively weaker states that are territorially contiguous to two
or more powerful neighbouring rival states. They may be either nominal or active
buer zones.
• Internal buer zones: Internal buer zones are geographic borderlands located within
states in rivalry and are adjacent to the international borders between the two rivals. Like
buer states, internal buer zones can only be understood in the context of
interstate rivalry. Some internal buer zones may mitigate rivalry conflict and
thus be considered active buers, while others remain nominal buer zones.
When states are suddenly getting weaker, for example as a result of the 
‘Arab Spring’ in the Middle East, their borderlands adjacent to rival states may
be amenable to becoming active internal buers. Such is the case of Libya’s
eastern borderland, where Egypt vies for influence against the ocial Libyan
government. This was also the case in Syria’s southern (adjacent to Israel) and
northern (adjacent to Turkey) borderlands. But the latter situation became what
we consider an external unilateral ‘security zone’ when Turkey invaded and
occupied the territory in  during the Syrian civil war.
 Ariel I. Ahram, Break all the borders: separatism and the reshaping of the Middle East (Oxford: Oxford University
Press, ); Leïla Vignal, ‘The changing borders and borderlands of Syria in a time of conflict’, International
Aairs : , , pp. –. Note that in many of these cases there are actors in addition to the rival states,
including other states and non-state actors, who are also involved in the power struggle within buer zones.

Boaz Atzili and Min Jung Kim

International Aairs 99: 2, 2023
• External unilateral ‘security zones’: These are areas of control established by a
stronger state within the boundaries of the weaker neighbouring state. These
‘security zones’ are usually created in response to non-state actors’ threats from
a weak neighbour and/or a revisionist state’s intention to expand the physical
and political control beyond its borders. As we discuss below, external unilateral
‘security zones’ are not necessarily a phenomenon related to interstate rivalry
and hence lie outside the scope of this article.
Active buffers as mechanisms of conict mitigation in relations of inter-
state rivalry
We focus on buer zones in the context of interstate rivalry—a dyadic approach
to the study of conflict. The emerging empirical consensus is that rival states are
much more likely to engage in armed conflict than other dyads of states. In
particular, disputed territories or boundaries play a large role in the origins of
interstate rivalries and conflict between rivals. Some rival dyads can achieve
‘territorial boundary peace’ through territorial conflict management. However,
little attention has been given to theorizing how rival states can strategically use
weak states or their subnational territories—buers—as conflict management
mechanisms.
Theoretically, buers can mitigate interstate conflict through at least four
mechanisms. First, robust empirical evidence suggests that contiguous states are
much more likely to fight each other than states that do not share a border.
Creating a buer territory between the two rival states negates contiguity by
generating physical distance, or at least decreasing the extent of the territory in
which they are contiguous. This could reduce the likelihood of conflict in several
ways. First, the greater the distance militaries need to travel, the less likely states
are to deploy troops and weaponry to attack a rival territory. For most states in
the international system, the loss of strength gradient is so steep that they can only
interact militarily with their immediate neighbours and therefore are incapable
of waging conflict with non-contiguous states. A buer creates challenging
and unfavourable logistics for military action by increasing opportunity costs for
 See e.g. James P. Klein, Gary Goertz and Paul F. Diehl, ‘The new rivalry dataset: procedures and patterns’,
Journal of Peace Research : , , pp. –; Michael P. Colaresi, Karen Rasler and William R. Thompson,
Strategic rivalries in world politics: position, space and conflict escalation (Cambridge: Cambridge University Press,
); Paul F. Diehl and Gary Goertz, War and peace in international rivalry (Ann Arbor, MI: University of
Michigan Press, ).
 William R. Thompson, Kentaro Sakuwa and Prashant Hosur Suhas, Analyzing strategic rivalries in world politics:
types of rivalry, regional variation, and escalation/de-escalation (Singapore: Springer, ); Diehl and Goertz, War
and peace in international rivalry.
 Gary Goertz, Paul F. Diehl and Alexandru Balas, The puzzle of peace: the evolution of peace in the international system
(Oxford: Oxford University Press, ).
 Paul R. Hensel, ‘Territory: theory and evidence on geography and conflict’, in Sara McLaughlin Mitchell and
John A. Vasquez, eds, What do we know about war? (Lanham, MD: Rowman & Littlefield, ), pp. –;
Stuart A. Bremer, ‘Dangerous dyads: conditions aecting the likelihood of interstate war, –’, Journal
of Conflict Resolution : , , pp. –; Randolph M. Siverson and Harvey Starr, ‘Opportunity, willing-
ness, and the diusion of war’, American Political Science Review : , , pp. –.
 Kenneth E. Boulding, Conflict and defense (New York: Harper and Row, ).

Buer zones and international rivalry

International Aairs 99: 2, 2023
military power projection. Thus, states will be less likely to initiate militarized
conflict with their rivals if they are separated by a buer territory.
Second, the distance created by buers between the rival states aects the
oence–defence balance in favour of the latter. Generally speaking, geography,
including distance, favours defenders. If the attacker must travel far to reach the
defender’s territory, its power projection capability is significantly reduced by the
costs of transporting and supplying the projected military force. In particular,
if the intervening distance is occupied by neutral or hostile states, the attacker’s
projected power is further curtailed by the costs of overcoming potential resistance
from these territories. Furthermore, distance makes surprise attacks less likely by
allowing the defending state time to organize, thus reducing the severity of the
security dilemma and the prospects of inadvertent wars that may result from it.
Third, research shows that militarized interstate disputes short of war (MIDs) are
strongly aected by proximity and contiguity. MIDs between countries that share
borders are more likely to erupt and escalate into wars. One reason for this is that
greater proximity of border patrols could result in military confrontation arising
from mistakes or unauthorized initiatives by local commanders. Some transnational
movements, such as rebels seeking safe havens or armed refugees, could further
result in clashes on the border or even interstate wars.
Lastly, buer zones may serve as a ‘pressure valve’, enabling the two rivals to
blow o steam without immediate danger of war. The two rivals can still compete
for influence and power within the buer zone, but they do so in a lower-risk
arena and through non-military means, making escalation less likely. In this case,
the existence of a buer does not make the interstate competition go away, but it
makes the stakes of the competition less critical to the vital interests of the rival
states, and hence less likely to spark a wider conflict.
The conflict mitigation function of buers varies depending on the interaction
between the two rival powers. In this sense, buers are neither uniform nor static;
they are highly contingent upon the power politics of their adjacent contestants.
In other words, buers are what rival states make of them. In a later section
below, we discuss how this function is determined.
Why unilateral external ‘security zones’ are not buffer zones
In both popular media and scholarship, a situation where a stronger state unilat-
erally gains control of territory inside a weaker neighbour’s boundaries is often
 Robert Gilpin, War and change in world politics (Cambridge: Cambridge University Press, ).
 Charles L. Glaser and Chaim Kaufmann, ‘What is the oense–defense balance and can we measure it?’, Inter-
national Security : , , p. .
 Stephen van Evera, Causes of war: power and the roots of conflict (Ithaca, NY: Cornell University Press, ).
 Paul R. Hensel and Hein Goemans, ‘Territory and contentious issues’, in McLaughlin Mitchell and Vasquez,
eds, What do we know about war?, pp. –; Paul F. Diehl, ‘Contiguity and military escalation in major power
rivalries, –’, Journal of Politics : , , pp. –.
 Salehyan, Rebels without borders; Sarah Kanyon Lischer, Dangerous sanctuaries: refugee camps, civil war, and the dilem-
mas of humanitarian aid (Ithaca, NY: Cornell University Press, ); Boaz Atzili, Good fences, bad neighbours:
border fixity and international conflict (Chicago: University of Chicago Press, ).
 We thank an anonymous reviewer for highlighting this point.

Boaz Atzili and Min Jung Kim

International Aairs 99: 2, 2023
conceived of as a particular kind of buer zone. Some examples include the
Israeli ‘security zone’ in southern Lebanon (–), Turkey’s ‘security zone’
in northern Syria, Russia’s dominant presence in Abkhazia and South Ossetia
within Georgia, and areas along Somalia’s borderlands surrounded by regional
powers. While these external security zones are interesting and important, they
lie outside our conceptual framework for two reasons. First, unilateral external
‘security zones’ often lack the context of interstate rivalry, which is essential to
understanding both internal buers and buer states. These security zones were
created in response to non-state actors’ threats from a weak neighbour and/or a
revisionist state’s intention to expand physical and political control beyond its
borders. These zones are thus more what one may define as spheres of influence
rather than buer zones.
Second, while active buer zones work to mitigate conflict between rivals by
creating a space that separates rival forces or making an assault by one against
the other harder, unilateral ‘security zones’ often exacerbate conflict within the
occupied territory or at the shared international borders, owing to increasing
presence of the intervenor. Establishing external ‘security zones’ allows a stronger
state to advance its forces or proxies in a way that may create space between the
international boundary and the threat (often a non-state actor), but not between
the rival forces. For example, Israel could shield its northern border from attacks
or rockets emanating from southern Lebanon through its -year occupation. At
the same time, however, Israeli forward operating bases in Lebanon increased
contact with Hezbollah, resulting in constant clashes. For these reasons, we
exclude external unilateral ‘security zones’ from our framework of analysis.
Territoriality, change and buffer zones
Buer zones are often conceived of as relics of the past, but we beg to dier.
Arguments can be made that buer zones are obsolete nowadays owing to the
advancement of military technology or changes in international ideas and norms
of borders. We maintain that while these changes may alter the way that buers
function in relations between states, neither of them actually makes buer zones
obsolete. We discuss each of these arguments in turn.
 Sela, ‘Civil society, the military’; Lazar Berman, ‘Two decades on, Israel confronts legacy of “forgotten”
South Lebanon occupation’, Times of Israel,  July .
 Aaron Stein, ‘The origins of Turkey’s buer zone in Syria’, War on the Rocks,  Dec. ; Asli S. Okyay,
‘Turkey’s post- approach to its Syrian border and its implications for domestic politics’, International Aairs
: , , pp. –.
 Margarita Antidze, ‘Russian buer zone in Georgia includes key road’, Reuters,  Aug. ; Gearóid Ó.
Tuathail, ‘Russia’s Kosovo: a critical geopolitics of the August  war over South Ossetia’, Eurasian Geogra-
phy and Economics : , , pp. –.
 Seyoum Mesfin and Abdeta Dribssa Beyene, ‘The practicalities of living with failed states’, Dædalus : ,
, pp. –.
 Menon and Snyder, ‘Buer zones’.
 Daniel Sobelman, ‘Learning to deter: deterrence failure and success in the Israel–Hezbollah conflict, –’,
International Security : , , pp. –.

Buer zones and international rivalry

International Aairs 99: 2, 2023
One may argue that buer zones became inconsequential in the modern era as
new military technologies, such as ballistic missiles, precision-guided munitions
and air power more broadly made state sovereignty irrelevant. As early as the
s, John Herz argued that the territorial state was facing its demise as it would
no longer be the most ecient supplier of security, given new military technolo-
gies. Herz himself, though, reversed this position a decade later, noting that the
potent power of nationalism seemed to be reverting these trends and averting
the demise of the territorial state. Air power, particularly precision-guided
munitions and drones, has altered modern warfare, but these mechanisms do not
negate the need to take control of territory to win a war, and for that there is no
substitute for ground forces. ‘Decapitation’, or targeting command and control,
has limited eciency without sucient territorial control on the ground, as the
United States learned in Afghanistan and Iraq. Nor does targeting civilian infra-
structure, as Israel did in  in Lebanon and as Russia is attempting to do in
Ukraine on a much larger scale, achieve victory without the ability to conquer
territory. And to conquer territory one needs to cross the buer zone, if it exists.
Indeed, the contemporary salience of cross-border phenomena, such as refugees,
pandemics, ‘new wars,’ economic interdependence and climate change, seems
only to harden territoriality and borders.
The eect of changing border norms on buer zones is more complex. Indeed,
the nature of buer zones underwent significant transformation with changes in
commonly held ideas and practices about territoriality and borders. We briefly
survey here the modern history of these changes and connect them to both buer
states and internal buers.
Three distinct but interrelated processes—the Westphalian model of the
sovereign state, the shift to linear ‘hard’ borders and the rise of the ‘territorial
integrity’ norm—changed how we perceive territories and hence buer zones.
These three processes are often conflated in the literature. First, the  Peace
of Westphalia is widely accepted as the historical birth of the modern European
state system based on the principles of territorial sovereignty. Yet scholars often
overlook the fact that Westphalia focused on territories and not on the delinea-
tion of borders.
Second, today we often think of borders as linear features that mark a ‘hard’
break between sovereign states. Yet this territorial order has not been the norm
 John H. Herz, ‘Rise and demise of the territorial state’, World Politics : , , pp. –.
 John H. Herz, ‘The territorial state revisited: reflections on the future of the nation-state’, Polity : , ,
pp. –.
 Robert A. Pape, Bombing to win: air power and coercion in war (Ithaca, NY: Cornell University Press, );
Robert A. Pape, ‘The true worth of air power’, Foreign Aairs : , , pp. –.
 See e.g. Michael R. Kenwick and Beth A Simmons, ‘Pandemic response as border politics’, International Organ-
ization : S, , pp. E–.
 Kerry Goettlich, ‘The rise of linear borders’, European Journal of International Relations :, , pp. –;
see also Beth A. Simmons and Hein E. Goemans, ‘Built on borders: tensions with the institution liberalism
(thought it) left behind’, International Organization : , , pp. –.

Boaz Atzili and Min Jung Kim

International Aairs 99: 2, 2023
historically, especially in peripheral and relatively sparsely populated areas.
Boundaries between political entities were often seen as ‘soft’ or ‘vague’ buers,
frontiers or spheres of influence, such as those at the margins of the Ottoman
empire or the Han Chinese empire. Even in post-Westphalia Europe, boundaries
mostly resembled vaguely defined frontiers rather than the clear linear borders
with which we are familiar in today’s world. As Jordan Branch finds, the idea
and practice of linear borders started not in Europe but through the interaction of
European colonizers with their possessions in the Americas. It became common-
place in Europe only after the early nineteenth century. Even then, Europeans
did not apply the ideas of linear borders to their colonies until much later in the
nineteenth century, when modern mapping and demarcation technology were
introduced.
Third, even if borders are conceived of in linear terms—on the map or on
the ground—it does not mean that these lines are fixed and unchangeable. In
the twentieth century, the territorial integrity norm adopted exactly this idea:
formal borders of homeland territories should not be changed by force. The
term ‘territorial integrity’ is often conflated with the Westphalian model of
sovereignty, but this norm is more about borders than sovereignty. The idea that
formal international borders should not change, certainly not by force, did not
originate in Europe. It first emerged in Latin America in the second half of the
nineteenth century, in the form of the uti possidetis juris principle (the idea that
colonial boundaries must be preserved after independence of new states), and was
later adopted in other regional institutions in the Middle East and Africa, as well
as in the UN. Only in the mid-s was it fully adopted in a European-centred
accord. To sum up, whereas territorial sovereignty was gradually adopted as a
rule at a systemic level starting in Europe in the late seventeenth century, linear
borders became a prevalent idea only in the late nineteenth century. The territo-
rial integrity norm, moreover, was not widespread before the second part of the
twentieth century.
Buer states have been aected by these changing ideas of sovereignty, terri-
toriality and borders in two ways. First, as Stephen Krasner argued, Westpha-
 Boaz Atzili and Burak Kadercan, ‘Territorial designs and international politics: the diverging constitution of
space and boundaries’, Territory, Politics, and Governance : , , pp. –; John Agnew, ‘The territorial
trap: the geographical assumptions of International Relations theory’, Review of International Political Economy
: , , pp. –.
 Jerey Herbst, States and power in Africa: comparative lessons in authority and control (Princeton, NJ: Princeton
University Press, ); James Scott, The art of not being governed: an anarchist history of upland southeast Asia (New
Haven, CT: Yale University Press, ).
 See, respectively, Burak Kadercan, ‘Territorial design and grand strategy in the Ottoman empire’, Territory,
Politics, Governance : , , pp. –; Chun-shu Chang, The rise of the Chinese empire: frontier, immigration,
and empire in Han China, 130 BC–AD 157 (Ann Arbor, MI: University of Michigan Press, ).
 Goettlich, ‘The rise of linear borders’.
 Jordan Branch, ‘“Colonial reflection” and territoriality: the peripheral origins of sovereign statehood’, Euro-
pean Journal of International Relations : , , pp. –.
 Mark W. Zacher, ‘The territorial integrity norm: international boundaries and the use of force’, International
Organization : , , pp. –; Fazal, State death.
 Atzili, Good fences, bad neighbours.
 The Helsinki Accords.

Buer zones and international rivalry

International Aairs 99: 2, 2023
lian sovereignty has never been fully applied in practice. Sovereignty, as Stuart
Elden shows, is contingent, depending on the actor and the act. This limited
application of sovereign principles is particularly pronounced in buer zones,
as powerful rivalling neighbours can and often do exert their influence over the
weaker state to compete with their rivals. The second aspect is the transformation
of buer states since the Second World War. In her foundational work on ‘state
death’, Fazal concluded that pre-Second World War buer states were more likely
to ‘die’ than any other states, as powerful neighbours could easily conquer and
annex them and had the motivation to do so. As Fazal acknowledges, however,
this important insight is less relevant to the postwar buer cases. As territorial
conquests dramatically declined, postwar states, including buer states, increased
in capacity to survive. This implies that buer states in the postwar era may
exemplify dierent characteristics from those of the past.
Similarly, internal buers may be aected even more by changes in concepts of
territoriality and borders. Most independent states after the Second World War
adopted the principle of linear borders with the assumption that the state authority
reaches all the way to the international borders. Even when states do not agree
on the location of the boundary, in most cases they still agree that there should
be a clear line delineating two states. For example, independent India inherited
the contested McMahon Line—the eastern sector Himalayan border separating
it from Chinese-controlled Tibet—from its colonial predecessor. However, its
actual control of the territory varied greatly over time. One could consider that
some of the Indian territories adjacent to China could be regarded as internal
buers, alternating between nominal and active roles during the course of Indo-
Chinese rivalry. Internal buers, then, are in many ways spaces entrapped in a
historical mismatch: they are areas of premodern territorial boundaries forced
into a formally modern territorial order. They are stubbornly persistent ‘frontier
areas’, grey zones of state power and authority that are incompatible with the
modern image of clear and fixed lines separating territories and peoples.
Second, states may also use borderlands strategically to manage external security
pressures. Some internal buers may be less penetrated by the state owing to inter-
state security concerns. Existing literature in both IR and comparative politics
tends to treat these pockets of seemingly ‘ungoverned’ or ‘undergoverned’ terri-
tories within state boundaries as a function of state weakness and failure, poten-
tially resulting in serious instability posing threats to the international system.
 Stephen D. Krasner, Sovereignty: organized hypocrisy (Princeton: Princeton University Press, ).
 Stuart Elden, Terror and territory: the spatial extent of sovereignty (Minneapolis: University of Minnesota Press,
).
 Fazal, State death. For an argument about the limitation of the territorial integrity norm, see Dan Altman,
‘The evolution of territorial conquest after  and the limits of the territorial integrity norm’, International
Organization : , , pp. –. However, as exemplified by the recent Russian invasion of Ukraine, the
strong and widespread condemnation by the international community of this norm’s violation could suggest
that the norm is still relevant.
 Goettlich, ‘The rise of linear borders’.
 Bérénice Guyot-Réchard, Shadow states: India, China and the Himalayas, 1910–1962 (Cambridge: Cambridge
University Press, ).
 Robert I. Rotberg, ed., When states fail: causes and consequences (Princeton: Princeton University Press, );

Boaz Atzili and Min Jung Kim

International Aairs 99: 2, 2023
Some weak states, the argument goes, lack sucient incentives and/or capacity to
monopolize the use of violence within their territories.
We argue instead that this general lack of governance and territorial control in
some borderlands could be at least partially a function of inter-rivalry interactions.
The dominant view in the state-building literature suggests that external threats
provide powerful motivation for territorial consolidation. When applying
buer logic, however, one can consider several alternative explanations. First,
some states may intentionally create fragmented and less penetrable territories in
their border regions to deter hostile external actors. In other words, states may
choose not to control certain territories along the frontiers owing to their internal
security concerns: an example would be Thailand’s approach to its western
frontiers adjacent to Myanmar during the Cold War. Second, internal buer
zones may be an arena in which, regardless of sovereignty, rival states compete for
influence. Also, states may be constrained in projecting their authority within
defined borders owing to implicit or explicit territorial arrangements with neigh-
bouring rivals, such as in the Korean Peninsula’s demilitarized zone and Egypt’s
Sinai Peninsula.
Conceptualizing buffer zones: a typology
Dyadic typology of buffer zones
In this section, we oer a typology that may help to conceptualize and explain
the dynamics of buer zones. Our dyadic model proposes that the emergence of
active buers at the state and subnational levels is a product of the level and kind
of interaction between two neighbouring rival states vis-à-vis the buer zones.
We identify three types of rival’s interaction—competitive engagement, construc-
tive engagement and disengagement—within buer territories, and they can be
measured in terms of the balance of military, political and economic interven-
tions/investments of the rival states within buers. In competitive engagements,
both states in a rivalry invest significantly in attempts to gain influence over the
buer territory. Constructive engagements occur when the rival states engage in
cooperation to reach a formal or tacit agreement about the ‘rules of the game’
within the buer territory. This can only work if it is mutual; one-sided coopera-
tion will last for only a short time if not reciprocated by the rival state. Disengage-
ment is a situation where neither state in a rivalry invests significantly in gaining
influence within the buer territory.
Anne Clunan and Harold Trinkunas, Ungoverned spaces: alternatives to state authority in an era of softened sovereignty
(Stanford, CA: Stanford University Press, ).
 Among many others, see Charles Tilly, Coercion, capital, and European states, AD 990–1990 (Malden, MA: Black-
well, ).
 Paul Battersby, ‘Border politics and the broader politics of Thailand’s international relations in the s: from
communism to capitalism’, Pacific Aairs : , , pp. –.
 Lee, Crippling Leviathan.
 John Chay, ‘Korea, a buer state’, in John Chay and Thomas Ross, eds, Buer states in world politics (Boulder,
CO: Westview, ); Nicolas Pelham, Sinai: the buer erodes (London: Chatham House, Sept. ).

Buer zones and international rivalry

International Aairs 99: 2, 2023
For the sake of this typology, we are agnostic as to what determines the level of
rivalry engagement. Instead, we focus on its behavioural outcomes. Indeed, these
determinants may include the agency of the buer zones themselves. For instance,
rough terrain—such as high mountains and/or dense jungles—within buer
territories may inhibit the levels of rival states’ engagement. The governments
of the buer territories may decide, on the basis of military, historical, cultural
or economic considerations, to ally with one rival rather than the other. Or the
buer’s own military forces might create a disincentive for the rivals to pursue
risky military operations within the buer territories. All of these are forms of
buer agency, which may aect the levels of the rival states’ engagement. While
buer agency should not be neglected, then, it plays an indirect role in aecting
the motivation and the chances of success in inter-rivalry interactions.
Figure  represents how dierent kinds of rivalry engagement produce nominal
buer zones and three types of active buers. These active buers allow conflict
mitigation between rivals more readily, but each type exhibits dierent conflict
mitigation dynamics. This typology acknowledges the heterogeneity of buer
zones and provides a framework for exploring how varying dyadic interactions
produce qualitatively dierent buer types.
 See Martin J. Bayly, ‘Imperial ontological (in)security: “buer states”, international relations and the case of
Anglo-Afghan relations, –’, European Journal of International Relations : , , pp. –.
 For a detailed discussion of typological theory, see Alexander George and Andrew Bennett, Case studies and
theory development in the social sciences (Cambridge, MA: MIT Press, ), pp. –.
Level of engagement
within buers
Rival 1
Competitive
engagement
Disengagement Constructive
engagement
Rival 2
Competitive
engagement
Box 1
Active buer
‘zone of contes-
tation’
Box 2
Nominal buer
(dominance of
rival )
X
Disengage-
ment
Box 3
Nominal buer
(dominance of
rival )
Box 4
Active buer
‘zone of neglect’
X
Constructive
engagement
X X Box 5
Active buer
‘zone of
management’
Figure 1: A typology of buer zones

Boaz Atzili and Min Jung Kim

International Aairs 99: 2, 2023
The following sections discuss each buer type in more detail through short
illustrative cases. These cases illustrate how rivalling states engage within nominal
and active buers and shape interstate security dynamics.
Nominal buffers (boxes 2 and 3)
Nominal buer zones fail to become active buers when one rival state is signifi-
cantly more engaged within the buer zone than the other. Asymmetric rivalry
engagement leads to a situation where one rival state becomes dominant within the
buer territories. At the subnational level, the sovereign state may exert a strong
presence in and control over its borderlands, or a dominant rival may carve out a
territory within geographic buers located within its rival territory, to establish
a sphere of influence (thus creating external buer zones), such as Russian influ-
ence over South Ossetia or Israeli control of the Golan Heights since . Buer
zones in this situation may be more dependent on or politically aligned with the
dominant rival. Nominal buers serve more as an extension of the dominant
rival’s interest and power than as a tension-mitigating role that separates forces
between the rival states.
For instance, Belarus is a nominal buer state in the Ukraine–Russia rivalry
as it is significantly weaker than its rivalling neighbours. While it shares a land
border with both Ukraine and Russia, Belarus has been closely allied with Russia
in the economic, political and military spheres since the mid-s, preventing
it from playing a role as an active buer zone. A growing Russian sphere of
influence in Belarus further destabilized the interstate relations between Russia
and Ukraine. Leading up to the  Ukrainian crisis, NATO reported that about
, Russian troops were stationed in Belarus, which served as a launching
ground for the northern flank of the Russian invasion of Ukraine.
Zone of contestation (box 1)
Competitive engagement of both rival states within buers creates one type of
active buer, which we refer to as the ‘zone of contestation’. In this case, an active
buer is not an intended outcome but rather a product of the equilibrium of the
rivals’ competition for influence within the buer. Competitive rivalry engage-
ment within buer territories creates an active buer zone because the two rivals’
influence in the buer zone is relatively equal, which means the buering quali-
ties of the zone remain intact: the main forces of the two rivals remain separated,
making military mobilization more dicult and more easily observable by the
rivals. Although the two rivals may engage in fierce competition for influence
within the buer zone, this competition is still relatively low-stakes: failure
does not immediately endanger their own homeland territory or vital interests.
 Randall E. Newnham, ‘Russia and Belarus: economic linkage in a patron–client relationship’, Journal of Bela-
rusian Studies : , , pp. –.
 Pavel Polityuk and Sabine Siebold, ‘NATO says Russia to have , troops on drills in Belarus, north of
Ukraine’, Reuters,  Feb. .

Buer zones and international rivalry

International Aairs 99: 2, 2023
Examples include Cambodia in the Thailand–Vietnam rivalry and Uruguay in the
Argentina–Brazil rivalry.
Lebanon is a buer state by virtue of its geopolitical location in the Syria–
Israel rivalry and also a ‘zone of contestation’ active buer owing to the competi-
tive military and political engagements by Israel and Syria. Lebanon is located
between the Mediterranean Sea to the west, Syria to the north and east, and Israel
to the south. Until the  Syrian civil war, both Lebanon’s neighbours possessed
a much stronger military and larger economies than Lebanon. Syria and Israel
have been rivals since the inception of the latter in , followed by three wars
in ,  and . They have been engaged in numerous militarized disputes
along their mutual border, and both view Lebanon as an important space in their
mutual rivalry.
In the first two decades of the State of Israel’s existence, Israeli–Syrian rivalry
was not focused on Lebanon. Instead, the rivalry played out in skirmishes along
their mutual border in the Israeli Hula valley and the Syrian Golan Heights. This
changed in the late s for several reasons. First, the  war proved to Syria that
Israel was a formidable rival and that direct attack would be risky and might end in
defeat. The  war reinforced that lesson to Syria, but it also showed Israel that
fighting directly against Syria could be costly. Second, for Israel, Lebanon became
an increasing source of threat as the Palestinian refugee camps became militarized
in the late s and began to serve as a staging ground for cross-border attacks and
terrorist infiltration. That trend escalated when the leading Palestinian organiza-
tion, Fatah, lost its base in Jordan and moved its headquarters to Lebanon. Third,
the Lebanese civil war, which erupted in , increased threat perceptions in both
Damascus and Jerusalem in the late s.
The Israeli–Syrian rivalry manifested itself in Lebanon through various
channels. First, both countries engaged in propping up and supporting proxies in
Lebanon. Israel sponsored the South Lebanon Army (SLA), a regional militia in
the south, and also secretly funded the Falangs Maronite militia. Syria supported
the Palestinian Liberation Organization (PLO) in its activity against Israel, before
turning against it in . As Dan Byman wrote: ‘By the end of Lebanon’s civil
war in  Syria had worked with every faction in Lebanon in constant attempts
to ensure that it remains the country’s powerbroker.’ Since the s, Syria has
been a major military, financial and political supporter of the Shi’a-dominated
Hezbollah. Second, both Syria and Israel intervened more forcefully and directly
in Lebanon through military means. Israel conducted a quick incursion into the
border regions of Lebanon in  to eradicate the PLO’s ability to conduct
cross-border attacks into Israel. Then in  it invaded Lebanon again and its
forces penetrated all the way to the outskirts of Beirut. It subsequently withdrew
 Lee, Crippling Leviathan; Michael Greenfield Partem, ‘The buer system in international relations’, Journal of
Conflict Resolution : , , pp. –; Joseph S. Tulchin, ‘Uruguay: the quintessential buer state’, in Chay
and Ross, eds, Buer states in world politics, pp. –.
 Boaz Atzili, ‘State weakness and “vacuum of power” in Lebanon’, Studies in Conflict and Terrorism : , ,
pp. –.
 Daniel Byman, A high price: the triumphs and failures of Israeli counterterrorism (Oxford: Oxford University Press,
), p. .

Boaz Atzili and Min Jung Kim

International Aairs 99: 2, 2023
but established a ‘security zone’ of several kilometres north of the international
border, which lasted until . Syria intervened in  in the guise of an ‘Arab
deterrence force’, and through this intervention secured direct military control of
the eastern Beqaa valley.
Third, both Israel and Syria sought to influence the Lebanese government to
a significant degree. Israel briefly dictated Lebanese politics in  when the
commander of the Israeli-friendly militia, Bashir Gemayel, was elected presi-
dent under conditions of an Israeli siege of Beirut. This victory was short-lived,
though, for Gemayel was assassinated shortly thereafter. Syria was much more
successful in achieving a lasting influence in Lebanon. From the  Ta’if Agree-
ment to the Syrian withdrawal in , Damascus had practically obtained veto
power over Lebanese national security and foreign relations policies. Lebanon
was still a ‘zone of contestation’ at that point though, given the continued occupa-
tion of southern Lebanon by the Israeli Defense Forces and the Syrian control
over Lebanese politics. Fourth, Israeli and Syrian forces actually clashed directly
in Lebanon in  as the Israeli invasion led to attacks on Syrian anti-aircraft
batteries and limited tank battles.
This competitive engagement between Israel and Syria enabled Lebanon to
serve as an active buer zone in several ways. First, especially before the  Israeli
occupation of the Golan Heights, Lebanon provided Syria, the weaker rival party,
with a buer that protected it from a surprise Israeli attack on its topographically
vulnerable western flank. Second, and more profoundly, Lebanon served as an
arena for fierce military and political confrontation between Syria and Israel. Yet
the two rivals were cautious not to allow their confrontation in Lebanon to spill
over beyond that space. In fact, notwithstanding their frequent confrontation on
their smaller and weaker neighbour’s soil, the Israeli–Syrian border in the Golan
Heights was largely quiet between their last war in  and the Syrian civil war
that started in .
Zones of contestation also include internal buer zones. One may consider the
Donbas region of Ukraine as an internal zone of contestation between Ukraine
and Russia. The region, geographically located between Russia and Ukraine, has
been an integral part of the newly sovereign Ukraine since . Nevertheless, it
has been the site of bitter rivalry for influence between the two rival states. While
a large majority of Donbas residents voted in  to be part of an independent
Ukraine, years of economic decline and corruption made the region, home to a
majority of Russian-speaking residents, into a fertile ground for Russian attempts
to compete against the authority of sovereign Ukraine. Russia did so by using
competing narratives and economic means to create an alternative political leader-
 Naomi Joy Weinberger, Syrian intervention in Lebanon: the 1975–76 civil war (New York: Oxford University
Press, ).
 Byman, A high price.
 Michael C. Hudson, ‘Lebanon after Ta’if: another reform opportunity lost?’, Arab Studies Quarterly : , ,
pp. –.
 Raymond A. Hinnebusch, ‘The foreign policy of Syria’, in Anoushiravan Ehteshami and Raymond A. Hinne-
busch, eds, The foreign policies of Middle East states: between agency and structure (Boulder, CO: Lynne Rienner,
), pp. –.

Buer zones and international rivalry

International Aairs 99: 2, 2023
ship and, ultimately, from  onwards, through assisting a violent rebellion.
At the same time, Ukraine attempted to consolidate and strengthen the Donbas
to suppress Russian influence in the region. In a sense, the Donbas served to
some degree as an active buer zone by mitigating a direct military confronta-
tion between the two rival states until . However, Russia’s taking control
of the region through a local proxy in , and then directly in , rendered
the region’s conflict mitigation functions moot. The Donbas became merely a
nominal buer from that point on.
Zone of neglect (box 4)
When the equilibrium within the buer zone is reached not by mutual engage-
ment but by mutual disengagement or lack of interest between rival states, the
result is a ‘zone of neglect’. In such a situation, the buer zone is an active one, as
the lack of infrastructure and governance in the area discourages troop mobiliza-
tion and deployment, as well as preventing close-range interaction with the rival’s
forces on the border.
India’s Arunachal Pradesh (formerly known as North East Frontier Agency)
between  and  is an example of a ‘zone of neglect’ resulting from mutual
disengagement between India and China. Arunachal Pradesh is a mountainous
tract of some , square kilometres bordered by Bhutan to the west, Tibet to
the north and Assam to the south. The area is also home to thinly populated ethni-
cally and linguistically heterogeneous hill tribes that were previously unincorpo-
rated by any state. The territory’s challenging geographic and climatic conditions
had historically deterred state penetration by the Chinese and British Indian
empires, so that it served as a ‘natural frontier’ between them.
Arunachal Pradesh is a disputed territory between India and China. On the
one hand, India insists that its sphere of influence extended to the region even at
the time of British colonial rule, as drawn in the McMahon Line by the colonial
map-makers in . On the other hand, China claims that its south-western
frontier territories, including Tibet, were historically part of the former imperial
domain. It further rejects the validity of the colonial boundary as China’s central
government of the time never agreed to it. This ill-defined Himalayan colonial
boundary was a major source of the  Sino-Indian War and featured promi-
nently in the enduring interstate rivalry over the next six decades.
 Tatyana Malyarenko and Stefan Wol, ‘The logic of competitive influence-seeking: Russia, Ukraine, and the
conflict in Donbas’, Post-Soviet Aairs : , , pp. –.
 Guyot-Réchard, Shadow states; Pran Nath Luthra, Constitutional and administrative growth of the North-East Fron-
tier Agency (Shillong: North-East Frontier Agency, ); Mosca W. Matthew, From frontier policy to foreign
policy: the question of India and the transformation of geopolitics in Qing China (Stanford, CA: Stanford University
Press, ).
 Alastair Lamb, The McMahon Line: a study in the relations between India, China, and Tibet, 1904–1914 (London:
Routledge, ); Neville Maxwell, India’s China war (Bombay: Jaico, ).
 T. V. Paul, ed., The China–India rivalry in the the globalization era (Washington: Georgetown University Press,
); John Garver, Protracted contest: Sino-Indian rivalry in the twentieth century (Seattle: University of Washing-
ton Press, ).

Boaz Atzili and Min Jung Kim

International Aairs 99: 2, 2023
Despite the historical significance of the disputed territory in interstate rivalry,
Arunachal Pradesh was largely neglected by both British India and its independent
successor until the Chinese annexation of Tibet in . From China’s viewpoint,
the disputed territory did not generate significant interest in a larger strategic
context. From India’s viewpoint, the challenging geographic and social terrains
of the Himalayas provided an ideal buer against Chinese invasion. This idea is
well articulated in Nehru’s speech to India’s parliament in :
From time immemorial, the Himalayas have provided us with magnificent frontiers. Of
course, they are no longer as impassable as they used to be, but they are still fairly eective.
We cannot allow that barrier to be penetrated [by China] because it is also the principal
barrier to India.
Accordingly, India continued to neglect to administer and establish eective
control of the territory, hoping that its ungoverned and challenging conditions
would serve as an eective buer against Chinese aggression. This logic continued
until India’s perception of the territory was altered owing to the Chinese annexa-
tion of Tibet. In response, India invested significantly in state resources and admin-
istrative expansion in the mid- to late s to control Arunachal Pradesh more
eectively. Consequently, Arunachal Pradesh has lost its active buer status as
it became more of an integral part of India’s borderlands, thus becoming a mere
nominal buer.
Today, the territory’s nominal buer status has intensified military confron-
tation between the formidable rivals, as seen in the border crisis since .
Without geographic separation for managing interstate rivalry and competition,
nominal buers are more likely to amplify mistrust and the security dilemma.
Zone of management (box 5)
When the two rival states engage constructively within the nominal buer zone
and informally or formally agree on the rules of the game, a ‘zone of management’
is established as a form of active buer. Examples include the demilitarized zone
(DMZ) in the Korean Peninsula after the  armistice agreement, and Austria
during the Cold War. These active buer territories are created through mutual
agreement between rival states to separate forces physically. The same geographic
separation may also prevent unintended clashes on the border. The level and type
of engagement of the two rivals within the buer zones may be determined by
formal or informal bilateral agreement.
 Dawa Norbu, ‘Chinese strategic thinking on Tibet and the Himalayan region’, Strategic Analysis : , ,
pp. –.
 Cited in Garver, Protracted contest, p. .
 Guyot-Réchard, Shadow states.
 Tanvi Madan, ‘China has lost India: how Beijing’s aggression pushed New Delhi to the West’, Foreign Aairs,
 Oct. , https://www.foreignaairs.com/china/china-has-lost-india.
 Chay, ‘Korea, a buer state’; Menon and Snyder, ‘Buer zones’; Audrey Kurth Cronin, East–West negotia-
tions over Austria in : turning-point in the Cold War’, Journal of Contemporary History : , , pp.
–.

Buer zones and international rivalry

International Aairs 99: 2, 2023
The Sinai Peninsula in Egypt has played a role as the ‘zone of management’ in
the Israel–Egypt rivalry since . Egypt and Israel have been bitter rivals since
the creation of the State of Israel in . The two countries fought five wars
between  and their peace agreement in , and even long after their peace
agreement, their relations fluctuated between ‘cold peace’ and ‘strategic rivalry’.
The Sinai Peninsula is located in Egypt, and lies between the Mediterranean Sea
to the north, the Red Sea to the south, the Suez Canal to the west and the Israeli
Negev (as well as the Palestinian Gaza Strip) to the east. By virtue of its topog-
raphy—a barren desert, some of it mountainous—and its sparse population, the
peninsula constitutes a natural buer between the two rivals. In , the terri-
tory served as a route for Egyptian forces to invade Israel, but the invasion was
unsuccessful owing to long and challenging logistic lines. In  Israel briefly
conquered the peninsula before being forced by the United States to retreat back
to its international borders. The  withdrawal of UN peacekeepers from Sinai
(at Egypt’s request) was a decisive factor in the process that led to a war and Israeli
reoccupation of the Sinai. Both the War of Attrition (–) and the Yom
Kippur/October War () were fought predominantly in the Sinai and around
the Suez Canal that separated it from the rest of Egypt.
The  peace accord between Israel and Egypt ended the state of war and
hostilities between the countries. At the heart of the agreement was Israeli consent
to withdraw back to its recognized international borders and acknowledge the
sovereignty of Egypt over the Sinai, in return for an Egyptian promise to keep
the Sinai demilitarized. Egypt committed itself to limiting the entry of heavy
weaponry to the Sinai, as well as the overall number of troops in the peninsula.
The agreement, which still remains in power today, has resulted in significant
easing of tension between the two states and no further wars, despite the constant
struggles of the Middle East.
The  peace agreement created a managed active buer zone in the Sinai
Peninsula. The most important buering role of the demilitarized zone is to create
a space between population centers and force concentrations on both sides. Any
large-scale mobilization for war by either side would need to cross a wide-open
space, including international inspectors, which would prevent a surprise attack
and allow diplomacy more time to find conflict-avoiding solutions. In addition, a
belt along the mutual border contained only a civilian police force on the Egyptian
side and a limited military force on the Israeli side to prevent a too-close interac-
tion between the militaries. A Multinational Force of Observers (MFO) was estab-
lished to supervise the continued adherence to the agreement’s provisions. In
 and , Israeli mechanized forces rolled across the international border and
quickly seized Egyptian border positions on their way towards the Suez Canal.
In , Egypt surprised Israeli forces along the canal with a massive attack that
found them unprepared. Such surprises are very unlikely to repeat themselves
with Sinai as an active buer zone.
 William B. uandt, Camp David: peacemaking and politics (Washington DC: Brookings, ).

Boaz Atzili and Min Jung Kim

International Aairs 99: 2, 2023
The main challenge in the Sinai today turns out to be not so much the Israeli–
Egyptian conflict but internal: the long neglect of the peninsula and its Bedouin
residents resulted in the rise of several Islamist groups aliated with Al-aeda and,
later on, Islamic Stste in Iraq and Syria (ISIS). These groups engaged in a protracted
bloody struggle against the Egyptian police and military, and made cross-border
attacks into Israeli territory. Interestingly, these new internal security challenges
led to a closer collaboration between Israel and Egypt, including Israeli permission
to Egypt to bring heavier military forces into Sinai, in excess of what the 
accord provided for, and, reportedly, Israeli drone attacks with tacit Egyptian
support. It seems that the existence of an active buer allowed transformative
relations to develop from rivalry to collaboration between Israel and Egypt.
Conclusions
Buer states today are unlikely to experience ‘state death’, which makes them less
vulnerable to the machinations of stronger rival neighbours than in past centuries.
Yet the strategic role of buer zones in conflict mitigation between rival states
persists.
This article has reconceptualized buer zones in three broad ways. First, we
dierentiated between nominal buer zones, which exist simply by virtue of their
geopolitical location, and active buer zones, which serve a role in mitigating
international conflict between rivals. Second, we made a case that buer zones
should include both states and subnational territories of a sovereign state adjacent
to borders between international rivals. Third, we developed a novel typology
based on the dyadic involvement of rival states within buer territories. In addition
to nominal buer zones, we identified three types of active buer zones—zones
of neglect, contestation and management—and discussed the internal logic and
dynamics of these territories through illustrative cases.
What is at stake in a more systematic and nuanced understanding of buer
zones? A theoretical framework does not by itself produce causal arguments or
allow for policy implications. These must come later in the research agenda. Yet
we can oer here a few preliminary conjectures.
First, our typology highlights the dierence between nominal and active buers
at both the state and intrastate levels. Understanding this dierence may have
important implications for explaining the dynamics of contemporary interstate
conflicts. For example, to the extent that Russia’s goal in invading Ukraine was
to create a buer between itself and NATO, our framework will show how that
goal was unattainable by way of conquest. Gaining control of Ukrainian territory
would make it a nominal, rather an active buer, and hence is unlikely to mitigate
conflict.
 Lisa Watanabe, ‘Sinai Peninsula: from buer zone to battlefield’, CSS Analyses in Security Policy, vol. 
(Zürich: EHT Zürich, ), pp. –.
 Zack Gold, Egypt’s war on terrorism (Washington DC: Carnegie Endowment for International Peace, );
Watanabe, ‘Sinai Peninsula’; Samira Shackle, ‘Unprecedented security cooperation between Egypt and Israel
in the Sinai’, Middle East Monitor,  Aug. .

Buer zones and international rivalry

International Aairs 99: 2, 2023
Second, various types of buers might result in dierent—and often contra-
dictory—security implications at dierent levels. A ‘zone of contestation’, for
example, may foster a more stable strategic environment between two rivals
while creating unstable conditions within buers, as the contestants may engage
in proxy warfare or regime change of buer states. A ‘zone of neglect’ may also
yield interstate stability but produce deteriorating human security conditions
within the buer zone because investment and development by the rival states are
generally lacking. Further, non-state groups can exploit the territories neglected
by the contestants to engage in violent attacks.
Future research should empirically examine these conjectures that arise out of
variations in the geopolitical location of a territory and the actions of the rival
states that surround them. In this sense, we hope this article opens a new and
important avenue of research on the role of buers in contemporary peace and
conflict in world politics.