Which unified combatant command headquarters is located at MacDill AFB, FL?

The unified combatant command headquarters located at MacDill Air Force Base in Florida is the United States Special Operations Command, often abbreviated as USSOCOM. This command is responsible for overseeing the various special operations forces from all branches of the U.S. military, ensuring they are trained, equipped, and ready to conduct special operations worldwide.

MacDill AFB serves as the central hub for USSOCOM's operations, underlining its significant role in coordinating special operations, which can include counter-terrorism, unconventional warfare, and direct action missions. The establishment of USSOCOM at this base allows for effective integration of special operations forces and joint training exercises with other military units.

In contrast, the other commands listed in the options are headquartered elsewhere: USCENTCOM is located at MacDill as well but focuses on operations in the Middle East; USNORTHCOM is based at Peterson AFB in Colorado and deals with homeland defense; and USINDOPACOM is headquartered in Camp Smith, Hawaii, and is responsible for operations in the Indo-Pacific region. Thus, recognizing the significance of USSOCOM's mission contributes to understanding the strategic military framework within these unified combatant commands.