Admiral Fallon departs U.S. Pacific Command, after serving two years with distinction, to assume the duties as Commander, U.S. Central Command, in Tampa, Fla. General Leaf will serve as Acting Commander until a new U.S. Pacific Command Commander is confirmed by the U.S. Senate and assumes command. President George W. Bush has nominated Admiral Timothy J. Keating, Commander, U.S. Northern Command, for appointment as Commander, U.S. Pacific Command. U.S. Pacific Command is the headquarters responsible for all American air, ground and maritime military forces in the Asia-Pacific region. U.S. Pacific Command is the largest geographical command in the Department of Defense. It encompasses 43 countries bordered by two oceans, encompassing an area that covers more than 100 million square miles from the West Coast of the United States to the East Coast of Africa. US Navy Photo by Mass Communications Specialist Second Class Alisha M. Frederick.