In the end of the war, Ex-nazi German official surrendered to the Americans. Some of them offered their knowledge about the Soviet Union in exchange to be spare from jail time or to be executed. However, later on it indicates that those Ex-nazi are telling nothing but lies about the Soviet Union, causing a lot of wasted resources for the American to expand their army.
What more worse is that those Ex-Nazi official would also work for the Soviet Union and steal american high secret information to the communists government.