weapons of mass destruction n.

"nuclear, biological and chemical weapons" attested by 1946, apparently first used (in Russian) by the Soviets.

The terms "weapons of mass destruction" and "WMD" mean chemical, biological, and nuclear weapons, and chemical, biological, and nuclear materials used in the manufacture of such weapons. [United States Code: Title 50, "War and National Defense," chapter 43, § 2902, 2009]