The effectiveness of the policy of massive retaliation is debated. Some historians argue that the policy was successful in deterring the Soviet Union from attacking the United States. They point to the fact that the Soviet Union never launched a nuclear attack on the United States during the Cold War. Others argue that the policy was not effective because it was based on the assumption that the Soviet Union would be rational and would not risk its own destruction by attacking the United States. However, the Soviet Union was not always rational and it is possible that the policy of massive retaliation could have led to a nuclear war.
Ultimately, the effectiveness of the policy of massive retaliation is difficult to determine. It is possible that the policy played a role in deterring the Soviet Union from attacking the United States, but it is also possible that the policy could have led to a nuclear war.