What does the oath promise?

The Oath of Allegiance promises support and defense of the Constitution and laws of the United States; this is the central commitment in the oath text set out in 8 CFR section 337.1. The full text contains six promises woven around the support-and-defend commitment. The first is renunciation of all prior foreign allegiance and fidelity to any foreign prince, potentate, state, or sovereignty. The second is the support-and-defend promise itself: the new citizen pledges to "support and defend the Constitution and laws of the United States of America against all enemies, foreign and domestic." The third is to bear true faith and allegiance to the same.

The fourth and fifth concern military and civilian service: to bear arms on behalf of the United States when required by law, and to perform noncombatant service in the Armed Forces when required by law. The sixth is to perform work of national importance under civilian direction when required by law. The oath closes with the declaration that the obligation is taken freely and without mental reservation.

The Constitution is identified by name as the object of the new citizen's support and defense, reflecting the supremacy of the Constitution under Article VI's Supremacy Clause. Federal officials take a similar oath under 5 U.S.C. section 3331, and Article VI, clause 3 requires that all federal and state legislative, executive, and judicial officers be bound by oath or affirmation to support the Constitution. The oath therefore aligns the duties of new citizens with the duties of public officials at every level of American government.