I hereby declare, on oath, that I absolutely and entirely renounce and abjure all allegiance and fidelity to any foreign prince, potentate, state, or sovereignty of whom or which I have heretofore been a subject or citizen; that I will support and defend the Constitution and laws of the United States of America against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I will bear arms on behalf of the United States when required by law; that I will perform noncombatant service in the Armed Forces of the United States when required by the law; that I will perform work of national importance under civilian direction when required by the law; and that I take this obligation freely without any mental reservation or purpose of evasion; so help me God. In acknowledgement whereof I have hereunto affixed my signature.
In some cases, INS allows the oath to be taken without the clauses:
" that I will bear arms on behalf of the United States when required by law; that I will perform non-combatant service in the Armed Forces of the United States when required by law "
More information on the Oath of Allegiance can be found in the Code of Federal Regulations, Title 8 (Aliens and Nationality), Chapter I, Part 337 (8CFR337).