The U.S. Armed Forces consist of 1.4 million active front-line personnel and an additional 1.1 million active reserve personnel, distributed between the Army, Navy, Air Force, Marines, National Guard and Coast Guard. The President of the United States is the principal decision-maker for military actions and strategy.
Each of the main branches of the military is further divided into an active branch and a reserve branch. Reserve personnel are individuals who generally work civilian jobs but who have volunteered to serve military duty as needed.
As of 2015, the United States operates over 6,000 tanks, 41,000 armored fighting vehicles and 1,000 land-based multiple-launch rocket systems. Over 13,000 individual aircraft, including between 900 and 1,200 attack helicopters, make up the total air power of the United States. The Navy operates 473 individual vessels; 20 of these are aircraft carriers, 62 are destroyers and 72 are submarines. These figures include inactive vessels.
The U.S. Armed Forces consume an estimated 19 billion barrels of oil every day. Yearly military expenditures made by the U.S. government exceed $500 billion dollars per year, or just over 4 percent of annual GDP. In addition to conventional fighting forces and units, the United States military also has access to a stockpile of 9,400 nuclear warheads.