Earlier Americans felt that Africans were lower than them because they looked different and originated from a different place.
Richard Nixon sent soldiers into Cambodia allegedly to destroy command and support facilities of north Vietnamese troops during the Vietnam war. So public outcry against the invasion of a neutral country resulted and then congress passed the war powers act
They were worried about the punishment that the south was gunna get.
The very first military setback for Adolph Hitler and his forces was the Battle of Britain. This occurred during WWII when Hitler was forced to cancel his planned invasion of Britain. This operation was known as Operation Sea Lion. He continued to bomb them but was unsuccessful in defeating them.