The Iguaza Falls, a once popular international tourist destination in the northeast corner of Argentina, is one of most beautiful places in South America. Located in the Tri Border Area (TBA), which is comprised of Puerto Iguazu, Argentina, Foz de Iguazu, Brazil, and Ciudad del Este, Paraguay, it is populated with between 12,000 to 40,000 Arabs and their descendants, as well as 30,000 Asians. The area is a lawless zone that is home to Islamic terrorists of Syrian and Lebanese descent and their sympathizers. Together they work in an informal economy of fund-raising, narcotics trafficking, smuggling (human and commercial), money laundering, document and currency fraud, and the manufacture/movement of pirated goods. The porous borders of the region enable terrorist operatives of Hezbollah, Hamas, al-Qaeda and their splinter groups to pass through the TBA, easily conducting criminal activities to support worldwide terrorism. The United States needs to do more to counter this threat in the Western Hemisphere. Even with terror groups on the run after three years of intense pressure since 9/11, Hezbollah, operates freely, especially in money laundering and the drug trade, in this South American safe-haven. Because of the full-time engagement of the United States in the Middle East, the threat has operated without the required level of attention of the United States for too long. A serious emphasis on the TBA is necessary for American security because of the region’s proximity to the United States. The diplomatic, informational, military, economic, intelligence and law enforcement (DIME) Plus Model provides a useful framework to analyze the issues in the TBA. The paper will identify what has worked in the past, and explain how certain conditions have created an environment in which terrorist groups operate in the region, and how their activities pose a threat to hemispheric security. It also and provides a robust checklist of recommendations to help both the Department of State and Southern Command (SOUTHCOM) remedy the problems. Ultimately, it will address how cooperation among the United States, Argentina, Brazil, and Paraguay can be improved to combat transnational terrorism in the TBA in a post 9/11 security environment. Using the DIME Plus Model in an engaged strategy gives America the tools to assist the TBA nations in their own efforts to work toward a future of success in the TBA. Mustering all the elements of U.S. power will strengthen the rule of law in the region and spawn economic development. U.S. projection of its national power tailored to the particular needs of each of the three countries of the TBA is the best way to resolve the persistent issues. A U.S strategy using the DIME Plus Model will build strong partnerships. Given its comprehensive structure and flexible implementation, it provides the most appropriate approach for this time. If America is to be secure, a fundamental change in the security situation in the TBA is essential.