United States v. Macintosh (1931) rejected that the First Amendment’s
protection of conscientious objectors extended to those applying for
citizenship.
Conscientious Objection and Religious Freedom
Conscientious objection to military service refers to the position taken by individuals who oppose participation in war on the basis of their religious, moral, or ethical beliefs. Such objection can take many forms, such as refusing to serve in combat, register for the draft, pay taxes tied to war allocations, or make any type of contribution to a war effort.
Several First Amendment rulings have considered religious freedom in conscientious objection disputes.
In 1965, the Supreme Court expanded the concept of religion that is
protected under the First Amendment in a case involving a conscientious
objector who did not believe in a single Supreme Being. In United States v.
Seeger, the Court moved away from requiring a theistic belief to qualify
for protection of religious freedom.