An Explanation of Oppenheimer

Freeman Dyson reviews a new biography of Robert Oppenheimer by Ray Monk, and gives some interesting perspective on his interactions with Oppenheimer (h/t Ritholtz):

The second occasion for me to talk with Oppenheimer about bombs came a few years later, when I was chairman of the Federation of American Scientists, a political organization of scientists concerned with weapons and arms control. The federation was opposing the US deployment of tactical nuclear weapons in exposed positions in Europe and Asia. We considered these deployments to be unacceptably dangerous, because nuclear-armed troops involved in local fighting could start a nuclear war that would quickly get out of control. When we examined the history of tactical weapons, we learned that Oppenheimer himself had flown to Paris in 1951 to persuade General Eisenhower, then in command of American forces in Europe, that the United States Army needed tactical nuclear weapons to defend Western Europe against a Soviet invasion. Oppenheimer had been enthusiastically promoting the production and deployment of tactical weapons.
After learning this, I went to see Oppenheimer and asked him directly why he had thought that tactical nuclear weapons were a good idea. This time, he answered my question. He said, “To understand why I advocated tactical weapons, you would have to see the Air Force war plan that we had then. That was the God-damnedest thing I ever saw. It was a mindless obliteration of cities and populations. Anything, even a major ground war fought with nuclear weapons, was better than that.”
I understood then how it happened that Oppenheimer came to grief. He was caught in a battle between the Army and the Air Force. The Army wanted small bombs to destroy invading armies. The Air Force wanted big bombs to destroy whole countries. The Army wanted fission bombs and the Air Force wanted hydrogen bombs. Oppenheimer was on the side of the Army. That was why he promoted tactical weapons. That was why he opposed the development of the hydrogen bomb.
The Air Force took its revenge on the Army by helping to drive Oppenheimer out of the government. Air Force General Roscoe Charles Wilson was one of the witnesses against Oppenheimer at the security hearing. General Wilson said, “I felt compelled to go to the Director of Intelligence to express my concern over what I felt was a pattern of action [on Oppenheimer’s part] that was simply not helpful to national defense.” In the eyes of the Air Force, anyone who opposed the hydrogen bomb was opposing national defense. The Air Force won the battle, and Oppenheimer’s friends in the Army could not help him. The hydrogen bomb development rushed ahead with the highest priority. But in the end, both the Air Force and the Army got all the bombs that they wanted.

In the end, Dyson is brutally critical of Oppenheimer's contributions to science.  But, as he mentions in the review, Oppenheimer was at the center of things throughout the early to mid 20th century.