Page:A Concise History of the U.S. Air Force.djvu/57

 August 1962 respectively) came in time to carry a whole new generation of miniature nuclear and thermonuclear warheads. The solid-propellant Minuteman ICBM series followed, beginning in October 1962, and became the mainstay of SAC's missile retaliatory force. The U.S. Air Force was becoming an aerospace force. Before ICBMs, manned bombers formed the strength behind the "New Look." Airmen had argued since World War I that air power was essentially offensive, but they were compelled to view it as defensive in light of the damage that resulted from the explosion of even one nuclear weapon. To detect incoming attacks, President Truman approved the Distant Early Warning (DEW) radar line which, with Canada's assent, was built across its northern territory beginning in 1954. To operate the line and coordinate their defensive forces, both the United States and Canada established on September 12, 1957, the binational North American Air Defense Command (NORAD). A generation of interceptor aircraft began service, beginning with the F-89 and F-100, succeeded by the F-102, F-106, and F-15. For a time anti-air defenses included surface-to-air missiles such as the Nike Ajax system. The development of several follow-up designs occurred, but none was deployed. In the early 1960s the Air Force reinforced NORAD with the Ballistic Missile Early Warning Sys -