Information:  - The United States Air Force ( USAF ) is the aerial warfare service branch of the United States Armed Forces and one of the seven American uniformed services . Initially part of the United States Army , the USAF was formed as a separate branch of the military on 18 September 1947 under the National Security Act of 1947 . It is the most recent branch of the U.S. military to be formed , and is the largest and one of the world 's most technologically advanced air forces . The USAF articulates its core functions as Nuclear Deterrence Operations , Special Operations , Air Superiority , Global Integrated ISR , Space Superiority , Command and Control , Cyberspace Superiority , Personnel Recovery , Global Precision Attack , Building Partnerships , Rapid Global Mobility and Agile Combat Support . The U.S. Air Force is a military service organized within the Department of the Air Force , one of the three military departments of the Department of Defense . The Air Force is headed by the civilian Secretary of the Air Force , who reports to the Secretary of Defense , and is appointed by the President with Senate confirmation . The highest - ranking military officer in the Department of the Air Force is the Chief of Staff of the Air Force , who exercises supervision over Air Force units , and serves as a member of the Joint Chiefs of Staff . Air Force combat and mobility forces are assigned , as directed by the Secretary of Defense , to the Combatant Commanders , and neither the Secretary of the Air Force nor the Chief of Staff have operational command authority over them . The U.S. Air Force provides air support for surface forces and aids in the recovery of troops in the field . As of 2012 , the service operates more than 5,638 military aircraft , 450 ICBMs and 63 military satellites . It has a $ 140 billion budget with 309,339 active duty personnel , 185,522 civilian personnel , 71,400 Air Force Reserve personnel , and 106,700 Air National Guard personnel .  - The First Barbary War (18011805), also known as the Tripolitanian War and the Barbary Coast War, was the first of two Barbary Wars between the United States, Sweden and the four North African states known collectively as the "Barbary States". Three of these were nominal provinces of the Ottoman Empire, but in practice autonomous: Tripoli, Algiers, and Tunis. The fourth was the independent Sultanate of Morocco. The cause of the war was pirates from the Barbary States seizing American merchant ships and holding the crews for ransom, demanding the U.S. pay tribute to the Barbary rulers. United States President Thomas Jefferson refused to pay this tribute, in addition the Swedes had been at war with the Tripolitans since 1800.  - The Congress of the Confederation, or the Confederation Congress, formally referred to as the United States in Congress Assembled, was the governing body of the United States of America that existed from March 1, 1781, to March 4, 1789. It comprised delegates appointed by the legislatures or assemblies of the several states. It was preceded by the Second Continental Congress (17751781) and governed under the newly adopted "Articles of Confederation and Perpetual Union", which were proposed 17761777, adopted by the Continental Congress in July 1778 and finally agreed to by a unanimous vote of all thirteen states by 1781, held up by a long dispute over the cession of western territories beyond the Appalachian Mountains to the central government led by Maryland and a coalition of smaller states without western claims. The newly reorganized Congress at the time continued to refer itself as the Continental Congress throughout its eight-year history, although modern historians separate it from the earlier bodies, which operated under slightly different rules and procedures until the later part of American Revolutionary War. The membership of the Second Continental Congress automatically carried over to the Congress of the Confederation when the latter was created by the ratification of the Articles of Confederation. It had the same secretary as the Second Continental Congress, namely Charles Thomson. The Congress of the Confederation was succeeded by the Congress of the United States as provided for in the Constitution of the United States, proposed September 17, 1787, in Philadelphia and ratified by the states through 1787 to 1788 and even into 1789 and 1790.  - World War II (often abbreviated to WWII or WW2), also known as the Second World War, was a global war that lasted from 1939 to 1945, although related conflicts began earlier. It involved the vast majority of the world's nationsincluding all of the great powerseventually forming two opposing military alliances: the Allies and the Axis. It was the most widespread war in history, and directly involved more than 100 million people from over 30 countries. In a state of "total war", the major participants threw their entire economic, industrial, and scientific capabilities behind the war effort, erasing the distinction between civilian and military resources. Marked by mass deaths of civilians, including the Holocaust (in which approximately 11 million people were killed) and the strategic bombing of industrial and population centres (in which approximately one million were killed, and which included the atomic bombings of Hiroshima and Nagasaki), it resulted in an estimated 50 million to 85 million fatalities. These made World War II the deadliest conflict in human history.  - The American Civil War was a civil war in the United States fought from 1861 to 1865. The Union faced secessionists in eleven Southern states grouped together as the Confederate States of America. The Union won the war, which remains the bloodiest in U.S. history.  - The Cold War was a state of political and military tension after World War II between powers in the Eastern Bloc (the Soviet Union and its satellite states) and powers in the Western Bloc (the United States, its NATO allies and others). Historians do not fully agree on the dates, but a common timeframe is the period (the second half of the 20th century) between 1947, the year the Truman Doctrine (a U.S. policy pledging to aid nations threatened by Soviet expansionism) was announced, and 1991, the year the Soviet Union collapsed.  - The Army of the United States or Armies of the United States is the legal name of the "land forces of the United States" (United States Constitution, Article 2, Section 2, Clause 1 and United States Code, Title 10, Subtitle B, Chapter 301, Section 3001) and has been used in this context since at least 1841, as in the title: "General Regulations for the Army of the United States". The Army, or Armies of the United States includes: the Regular Army, Army National Guard, and the Army Reserve, (as well as any volunteer or conscripted forces).   - The United States Army (USA) is the largest branch of the United States Armed Forces and performs land-based military operations. It is one of the seven uniformed services of the United States and is designated as the Army of the United States in the United States Constitution, Article 2, Section 2, Clause 1 and United States Code, Title 10, Subtitle B, Chapter 301, Section 3001. As the largest and senior branch of the U.S. military, the modern U.S. Army has its roots in the Continental Army, which was formed (14 June 1775) to fight the American Revolutionary War (17751783)before the U.S. was established as a country. After the Revolutionary War, the Congress of the Confederation created the United States Army on 3 June 1784, to replace the disbanded Continental Army. The United States Army considers itself descended from the Continental Army, and dates its institutional inception from the origin of that armed force in 1775.  - The National Security Act of 1947 was a major restructuring of the United States government's military and intelligence agencies following World War II. The majority of the provisions of the Act took effect on September 18, 1947, the day after the Senate confirmed James Forrestal as the first Secretary of Defense.  - The American Revolutionary War (17751783), also referred to as the American War of Independence and the Revolutionary War in the United States, was an armed conflict between Great Britain and thirteen of its North American colonies that after onset of the war declared independence as the United States of America.  - The United States of America has seven federal uniformed services that commission officers as defined by Title 10, and subsequently structured and organized by Title 10, Title 14, Title 32 and Title 42 of the United States Code.  - The Continental Army was formed by the Second Continental Congress after the outbreak of the American Revolutionary War by the colonies that became the United States of America. Established by a resolution of the Congress on June 14, 1775, it was created to coordinate the military efforts of the Thirteen Colonies in their revolt against the rule of Great Britain. The Continental Army was supplemented by local militias and troops that remained under control of the individual states or were otherwise independent. General George Washington was the commander-in-chief of the army throughout the war.  - The Code of Laws of the United States of America (variously abbreviated to Code of Laws of the United States, United States Code, U.S. Code, or U.S.C.) is the official compilation and codification of the general and permanent federal statutes of the United States. It contains 52 titles, and a further three titles have been proposed. The main edition is published every six years by the Office of the Law Revision Counsel of the House of Representatives, and cumulative supplements are published annually. The official version of those laws not codified in the United States Code can be found in United States Statutes at Large.  - The United States Armed Forces are the federal armed forces of the United States. They consist of the Army, Marine Corps, Navy, Air Force, and Coast Guard. The President of the United States is the military's overall head, and helps form military policy with the U.S. Department of Defense (DoD), a federal executive department, acting as the principal organ by which military policy is carried out. From the time of its inception, the military played a decisive role in the history of the United States. A sense of national unity and identity was forged as a result of victory in the First Barbary War and the Second Barbary War. Even so, the Founders were suspicious of a permanent military force. It played an important role in the American Civil War, where leading generals on both sides were picked from members of the United States military. Not until the outbreak of World War II did a large standing army become officially established. 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 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 and National Security Council.    Given the information above, choose from the list below the object entity that exhibits the relation 'allegiance' with the subject 'united states air force'.  Choices: - allies  - confederate states of america  - soviet union  - sweden  - union  - united states constitution  - united states of america
A:
united states constitution