Fifth Fleet
the U.S. naval force, headquartered in Bahrain, whose area of responsibility includes the Persian Gulf, Red Sea, Arabian Sea, Gulf of Oman, Gulf of Aden, and some of the Indian Ocean. The fleet helps protect U.S. interests in the Middle East, for example by ensuring the free flow of oil through the Strait of Hormuz and combating piracy. Its base in Bahrain is currently undergoing a $580 million expansion that will double its size.