The Fourth Fleet's area of responsibility (AOR) is within which geographic combatant commander's AOR?

The Fourth Fleet’s area of responsibility (AOR) falls under the U.S. Southern Command. This command is primarily responsible for U.S. military operations in Central and South America, as well as the Caribbean. The Fourth Fleet specifically focuses on naval operations and maritime security in these regions, which directly ties into the broader objectives of the U.S. Southern Command.

Understanding the geographic combatant command structures is crucial for effectively coordinating military operations, intelligence sharing, and logistics among different branches of the U.S. armed forces. The Southern Command's AOR includes a diverse range of countries and maritime areas, which necessitates a dedicated naval force like the Fourth Fleet to address unique challenges such as drug trafficking, humanitarian assistance, and disaster response in this dynamic environment.

In contrast, the other commands listed do not encompass the regions where the Fourth Fleet operates; hence, their areas of responsibility are not applicable in this context.