"To back up the massive retaliation strategy, the administration intended to give the nation's armed forces a "New Look." It called for major cuts in conventional and a massive buildup of nuclear weapons. During the Eisenhower years, the size of the army and navy was reduced, that of the air force increased- a reflection of the fact that air power, and particularly strategic air power, was going to primary component of the administration's massive retaliation strategy. In June 1953 the U.S. Air Force began ordering the nation's first intercontinental jet bomber, the B-52, which had a capability to deliver hydrogen bombs on Soviet targets. For long-term deterrence, however, the Eisenhower administration placed major emphasis on developing ballistic missiles. In 1955 the president approved the development of the Atlas missile, America's first intercontinental ballistic missile (ICBM), and its first intermediate-range ballistic missile (IRBM), the Thor. In 1957 the president approved still another air force ICBM, a solid-fueled missile, the Minuteman, which in the 1960s replaced the manned bomber as the primary component of the nation's strategic forces."