On November 15, 2001, Deputy Assistant Attorney General John Yoo sent a memo to Senior Associate Counsel John Bellinger, titled, ‘Authority of the President to Suspend Certain Provisions of the ABM Treaty.’ In reference to the 1972 Anti-Ballistic Missile treaty with the USSR, Yoo wrote that the President had the constitutional power to terminate and suspend any foreign treaties.
– John Yoo, “Authority of the President to Suspend Certain Provisions of the ABM Treaty” (memo to National Security Council), U.S. Department of Justice, Nov. 15, 2001