H.R. 3564 — The Nuclear First-Strike Security Act of 2025

This section limits the obligation or expenditure of appropriated funds to conduct a first-use nuclear strike—defined as a U.S. nuclear attack on a foreign country where the Secretary of Defense and Chairman of the Joint Chiefs of Staff have not jointly confirmed a prior nuclear attack by that country on the United States or an ally—unless (1) the President determines it is in the national interest and (2) the Secretary of Defense certifies the determination's validity and legality to the Speaker of the House, House Minority Leader, Senate Majority Leader, and Senate Minority Leader no more than seven days prior. The certification requirement does not apply to such strikes (1) under a congressional declaration of war, (2) in response to a nuclear attack (i.e., one or more nuclear detonations) on the United States or an ally (i.e., NATO member, Japan, Republic of Korea, or Australia), or (3) during a launch-on-warning scenario (i.e., detection of a missile launch toward U.S. or allied territory).