Effective July 21, 2015, new guidance (PA-2015-001) in the USCIS Policy Manual clarifies the eligibility requirements for modifications to the Oath of Allegiance. Reciting the Oath is part of the naturalization process. Candidates for citizenship normally declare that they will “bear arms on behalf of the United States” and “perform noncombatant service in the Armed Forces of the United States” when required by the law. A candidate may be eligible to exclude these two clauses based on religious training and belief or a conscientious objection.Conscientious objectors are still required to perform noncombatant service, and they are still subject to the duty to bear arms when required by law -- it's just that the law doesn't require them to bear arms so long as they serve in other capacities. Presumably that is going to be true for newly arrived immigrants as well.
But this is to ask, again, what is going on with citizenship? Citizenship is ultimately a mutual defense pact. We maintain our liberty by defending the liberty of our fellows, who defend ours in return. That's how we hold a space in the world in which to make real our vision of a just society.
Someone who won't participate in that is not properly a citizen. Under the 14th Amendment, if they were born here they have a legal right to be considered a citizen and treated as one. Yet they are violating the more basic nature of the bargain. Before there was a 14th Amendment, before there was a Constitution, before there could be a country needing a Constitution, people had to come together and pledge their lives, fortunes, and sacred honor to the mutual defense of each other and their liberties.
That's what it is really all about. If you have an objection to defending America's vision of liberty, don't apply for citizenship.