Why did people want to join the army in World War 2?

In the USA they wanted revenge on the Japanese for what they did at Pearl Harbor. Some wanted to fight in Europe to save the English and European people. Some did it because they needed a job badly after years of joblessness during the Great Depression. In the UK they did it to defeat the evil Nazis and save their country. Others joined out of patriotism and some even joined because their best buddy was doing it.