Nuclear Threat Reduction Act of 2001 - Repeals a provision of the National Defense Authorization Act for Fiscal Year 1998 which provides funding limits for retirement or dismantlement of the B52H bomber, Trident submarines, and Minuteman III and Peacekeeper intercontinental ballistic missiles. Declares it to be U.S. policy to: (1) reduce the number of nuclear warheads and delivery systems of the United States and Russia, through bilateral agreements, to the lowest possible number consistent with national security, requiring any warhead removed to be kept safe and secure, accounted for, and eventually destroyed or eliminated in a verifiable manner; (2) pursue with Russia formal arrangements to remove as many nuclear weapons of the two nations as possible from immediate, launch-ready status, beginning with those weapons earmarked for downloading, dismantlement, or elimination under the START II Treaty; and (3) work cooperatively with Russia to prevent the diversion from Russia of nuclear weapons, materials, and expertise.
Requires the President to submit to Congress a plan for nonproliferation programs with Russia, as well as a related study.