Which fleet is responsible for operations in South America?

The 4th Fleet is indeed the fleet responsible for operations in South America. It was re-established in 2008 to oversee U.S. naval operations in the Caribbean, Central America, and South America. This includes various missions such as humanitarian assistance, security cooperation, and maritime security.

The other fleets operate in different regions; for instance, the 1st Fleet primarily focuses on the Western Pacific and Indian Oceans, while the 3rd Fleet operates in the eastern Pacific. The 5th Fleet is primarily responsible for the Middle East, particularly the Arabian Gulf and surrounding areas. Hence, understanding the specific area of responsibility associated with each fleet is vital in recognizing the operational scope of the U.S. Navy's regional commands.