In January 1961, US President Dwight D Eisenhower used his farewell address to warn the nation of what he viewed as one of its greatest threats: the military-industrial complex composed of military contractors and lobbyists perpetuating war.

Eisenhower warned that "an immense military establishment and a large arms industry" had emerged as a hidden force in US politics and that Americans "must not fail to comprehend its grave implications". The speech may have been Eisenhower's most courageous and prophetic moment. Fifty years and some later, Americans find themselves in what seems like perpetual war. No sooner do we draw down on operations in Iraq than leaders demand an intervention in Libya or Syria or Iran.