America had no interest in the second world war they knew that they couldn't afford another war. The people were enjoying life and recovering from the last WW. They were happy. But Germany decided to sink a ship that boarded 1,400 Americans. And America Was tired. So they entered and Destroyed them. Many countries were included in the war. But they didn't have a set militia group. So many of the countries were defenseless. Especially against the German's who many very much feared. Adolf Hitler was killing Jews and Jehovah's Witnesses and many other social groups. And if you happened to be a Jew with Blond Hair and Blue eyes Hitler would offer to spare your life however most people proudly refused. He sent them to concentration Camps and gave them hard labor Jobs and if you weren't strong enough They would send you to the gassing chambers. After making you no to be able to breath so you would then die they would burn your bodies take the clothes you were wearing and give them to new members of the concentration camps.
I know I barley answered the question but yeah thats what WWII was like