What is WMD?

Weapon of mass destruction (WMD) is a term used to describe a massive weapon with the capacity to indiscriminately kill or incapacitate. The phrase broadly encompasses several areas of weapon synthesis, including nuclear, biological, chemical (NBC) and, increasingly, radiological weapons. There is controversy over when the term was first used, either in 1937 (in reference to the mass destruction of Guernica, Spain, by aerial bombardment) or in 1945 (with reference to nuclear weapons). Following the atomic bombings of Hiroshima and Nagasaki, and progressing through the Cold War, the term came to refer more to non-conventional weapons. The phrase entered widespread usage in relation to the U.S.-led 2003 invasion of Iraq. Terms used in a military context include atomic, biological, and chemical warfare (ABC warfare), nuclear, biological, and chemical (NBC) after the invention of the hydrogen bomb, and chemical, biological, radiological, and nuclear (CBRN), recognizing the threat of subcritical radiological weapons.