Referring to the Caribbean Basin as America's "third border," a report by the US Government Accountability Office (GAO) noted that the region has significant maritime links with the United States. Given these links and the region's proximity, the GAO said that the United States is particularly interested in ensuring that the ports in the Caribbean Basin - through which goods bound for US ports and cruise ships carrying its citizens must travel - are secure.

The Security and Accountability for Every Port Act of 2006 (SAFE Port Act) requires the GAO to report on various security-related aspects of Caribbean Basin ports. Its specific objectives were to identify and describe: threats and security concerns in the Caribbean Basin related to port security; actions that foreign governments and local stakeholders have taken in the Caribbean Basin to implement international port security requirements and the challenges that remain; activities reported to be under way by US government agencies to enhance port security in the Caribbean Basin, and; potential economic impacts of port security and terrorist attacks in the Caribbean Basin.

Writing in the report, Stephen L. Caldwell Director, Homeland Security and Justice Issues, stated:

"While intelligence sources report that no specific, credible terrorist threats to maritime security exist in the Caribbean Basin, the officials we spoke to indicated that there are a number of security concerns that could affect port security in the region."

"Caribbean ports contain a variety of facilities such as cargo facilities, cruise ship terminals, and facilities that handle petroleum products and liquefied natural gas. Additionally, several Caribbean ports are among the top cruise ship destinations in the world. Given the volume and value of this maritime trade, the facilities and infrastructure of the maritime transportation system may be attractive targets for a terrorist attack."

"Our prior work on maritime security issues has revealed that the three most likely modes of attack in the port environment are a suicide attack using an explosive-laden vehicle or vessel, a standoff attack using small arms or rockets, and the traditional armed assault. Beyond the types of facilities and modes of attack to be considered, officials we spoke to identified a number of overarching security concerns that relate to the Caribbean Basin as a whole."

Caldwell said that among these concerns are the level of corruption that exists in some Caribbean nations, organized gang activity occurring in proximity to or within port facilities, and the geographic proximity of many Caribbean countries, which has made them transit countries for cocaine and heroin destined for US markets.

Other security concerns in the Caribbean Basin mentioned by US agency officials include stowaways, illegal migration, and the growing influence of Islamic radical groups and other foreign terrorist organizations.