Page "Anti-Ballistic Missile Treaty" Paragraph 3

Throughout the late 1950s and into the 1960s, the United States and the Soviet Union had been developing a series of missile systems with the ability to shoot down incoming ICBM warheads.

During this period the US considered the defense of the US as a part of reducing the overall damage inflicted in a full nuclear exchange.

As part of this defense, Canada and the US established the North American Air Defense Command ( now called North American Aerospace Defense Command NORAD ).