RESTRAIN Act

HR 5894, the RESTRAIN Act, prohibits the United States from conducting any explosive testing of nuclear weapons or other nuclear explosions. It directly affects U.S. nuclear weapons programs by banning such testing using federal funds for fiscal year 2026 and beyond. The bill's key mechanism is a funding restriction: no money authorized for fiscal year 2026 or later may be used for explosive nuclear testing or other nuclear explosions. However, it explicitly excludes subcritical nuclear tests (which do not sustain a chain reaction) from this prohibition. The law aims to enforce a permanent ban on nuclear detonations while preserving the ability to conduct certain non-explosive testing.