Also, WMD. Weapons that can greatly harm or kill large numbers of people and/or severely damage man-made structures or the biosphere. The term was first used by the Archbishop of Canterbury in 1937 with reference to the aerial bombardment of Guernica, Spain. Less than a decade later, the term was applied to nonconventional weapons, specifically nuclear weapons. During the Cuban missile crisis of 1962, the term was used by President John F. Kennedy, referring to nuclear missiles. Fearing Iraq’s use of nuclear weapons, the alleged existence of such weapons became the main justification for the 2003 invasion of that country. By then, the term was so well known and so often abbreviated that it was on its way to clichédom.