The Soviet Union held the advantage of sheer number of soldiers at that time and U.S. officials thought that the only way to prevent Soviet aggression was to threaten a nuclear attack in response.
Kahn said that nuclear war was feasible and winnable. He argued that life would go on after such a war, whether a few major cities were destroyed or hundreds of millions of people died. He noted that in 14th century Europe life continued after the bubonic plague killed as many as 200 million people. Kahn argued that no matter how bad the devastation was survivors would "not envy the dead."
If you believed otherwise, Kahn said, then deterrence was unnecessary. If Americans weren't willing to push the button, then they ought not to be talking about attacking the Soviets, he said. For the idea to work, Soviets had to believe that the United States could not only survive a nuclear attack but that it could strike back. That belief in a "second strike" capability was paramount in convincing Soviet leaders that they would be destroyed if they attacked the United States, Kahn said.
Kahn incurred the anger of some people because he was perfectly willing to articulate what might happen if there were to be thermonuclear war, and what the world might look like when it was over. Some thinkers criticized Kahn for his ideas, saying that his suggesting that a nuclear war was winnable make it more likely that one would occur. However, prominent pacifists such as Bertrand Russell praised Kahn, saying his ideas made a strong case for disarmament.
Kahn was the inspiration for the title character in Stanley Kubrick's 1954 black comedy film Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb.