A joint US-Canadian approach to protecting North America lay behind the NORAD (North American Air Defense) agreement. This provided for joint protection of US and Canadian cities but did not specify any level of forces, equipment or facilities. NORAD quickly became not just the name of a pact but of a joint command, headquartered beneath tons of rock in Cheyenne Mountain near Colorado Springs in a fortress headquarters invulnerable to harm from anything but a direct hit by a heavy-megaton warhead. The NORAD chief was a US Air Force officer who controlled not only his service's assets but Canada's McDonnell CF-101B Voodoo interceptors.

With the gradual ascendancy of ICBMs and submarine-launched missiles, NORAD focused increasingly not so much on directing fighter-interceptors as on detecting Soviet missile launches. NORAD's missile warning role encompassed not just the air above the earth, but space itself. A large part of the command's surveillance resources were concerned with monitoring satellites using optical and electronic sensors located in many parts of the world. The Ballistic Missile Early Warning System radars scattered in various locations would, it was hoped, provide at least 25 minutes' warning of ICBM attack on the United States. New radars, noticeably Pave Paws, came into operation on the east and west coasts of the United States to improve warning against submarine-launched missiles.

It remained impossible to prevent Soviet warheads from arriving. While American and Canadian officers supervised those who peered into scopes at Colorado Springs, Air Force generals in the Pentagon concentrated on improving warning time, dispersing the American bomber force before an attack could catch them at their home bases, and launching a retaliatory strike. Not for another decade would some resources be devoted to anti-ballistic missile (ABM) radars and weaponry.