Causes of World War II

World War II started because a leader named Adolf Hitler wanted to take over all the countries around him. Hitler was the leader of a group called the Nazis, which was a powerful group in Germany. Hitler wanted more land and power, so he started invading other countries. The other countries around Germany didn't like this and they all teamed up in a "alliance" to try and stop Hitler. The United States and Great Britain also joined this alliance as they were scared of what Hitler was trying to do. They all declared war on Germany and its allies, and this is what started World War II.