“Give me the order to do it and I can break up Russia’s five A-bomb nests in a week,” he said. “And when I went to Christ, I think I could explain to Him why I wanted to do it now before it’s too late. I think I could explain to Him that I had saved civilization. With it [the A-bomb] used in time, we can immobilize a foe [and prevent] his crime before it happened.”
--Major General Orville Anderson, commandant of the Air War College, telling a newspaper reporter in 1950 that, given the authority to do so, he would order a nuclear strike against fledgling Soviet atomic capabilities.
From Jeffrey Record's Cato Policy Analysis "Nuclear Deterrence, Preventive War, and Counterproliferation," [.pdf], which outlines several occasions during the Cold War when America considered and, thankfully, rejected preventive nuclear war in the name of peace.