Why did World War 1 started? What were the effects?
Why did World War 1 take place? What were the political causes?
Why did World War 2 happen? What was the real cause of World War 2? How did World War 1 come to an end? Why did World War II happen? What was the reason behind World War II? What were the main countries involved in World War 1? How did they got involved? What started World War 2? Why did the U.S. become involved in World War II? Who started World War 2 and why? What started World War II? Why did Russia, Germany, France and UK enter World War 1? How did World War Two start? When did world war 2 end? What are three of the most significant causes of World War II? In summary, what events caused the start of the First and Second World Wars? Did World War 3 already start? Why did World Wars I and II happen? If World war 3 happened, what countries would likely start the war and why? What could cause a world war? What could cause a world war ? When did the World War end? Who started World War I and World War II? Why did the US and Vietnam War start? Why is World War 2 called "World" War 2 if it didn't affect the whole world? What important events happened in World War 2? What was World War II? Who won World War 1? Did world war 1 and 2 involve China? Why did Japan enter World War I? What was World War II about?