The United States Armed Forces is the armed forces of the United States of America. It consists of the Army, Marine Corps, Navy, Air Force, and Coast Guard. The President of the United States is the U.S. Armed Forces's overall head, and helps form military policy with the U.S. Department of Defense (DoD) and U.S. Department of Homeland Security (DHS), both federal executive departments, acting as the principal organs by which military policy is carried out. All five armed services are among the seven uniformed services of the United States. From the time of its inception, the U.S. Armed Forces played a decisive role in the history of the United States. The National Security Act of 1947, adopted following World War II and during the Cold War's onset, created the modern U.S. military framework; the Act merged the previously Cabinet-level Department of War and the Department of the Navy into the National Military Establishment (renamed the Department of Defense in 1949), headed by the Secretary of Defense; and created the Department of the Air Force (within the Defense Department) and the National Security Council. The U.S. Armed Forces is one of the largest militaries in terms of number of personnel. It draws its personnel from a large pool of paid volunteers; although conscription has been used in the past in various times of both war and peace, it has not been used since 1972, but the Selective Service System has 17 million males on record with the Selective Service. As of 2016, the U.S. spends about $580.3 billion annually to fund its military forces and Overseas Contingency Operations. Put together, the U.S. constitutes roughly 40 percent of the world's military expenditures. For the period 2010–14, the Stockholm International Peace Research Institute (SIPRI) found that the U.S. was the world's largest exporter of major arms, accounting for 31 percent of global shares. The U.S. was also the world's eighth largest importer of major weapons for the same period. The U.S. Armed Forces has significant capabilities in both defense and power projection due to its large budget, resulting in advanced and powerful equipment, and its widespread deployment of force around the world, including about 800 military bases in foreign locations. Added to this, the largest air force in the world is the U.S. Air Force. Moreover, the world’s second largest air arm is the U.S. Navy and the U.S. Marine Corps combined. The U.S. Navy is the largest navy by tonnage.