World War I was supposed to be the war to end all wars. Over 30 nations from around the globe were involved in this massive conflict. The major powers involved were Germany, Austria-Hungary, and the Ottoman Empire. These countries were known as the Triple Alliance. The triple threat. These were the "bad guys" so to speak. On the other side were France, England and Russia; The Triple Entente. I suppose you could also say that these were the "good guys". Every war must have a beginning. And usually war doesn't break out overnight. Especially so is in the case of a war of this magnitude. So what were the causes of World War I?.
Throughout Europe in the 1800s an idea began to spread throughout the land. This idea was Nationalism - "the belief that loyalty to a person's nation and its political and economic goals come before any other country's." In the case of Germany, a country didn't exist. There were these areas where like minded individuals lived together and they came together to form the nation. So then you have these groups of people who feel that they are far superior and know better than any other group of people. It is because of this that conflict was destined to break out in Europe. .
The US joined the war in the summer of 1917, joining the side of the England and France. Soon the war was over, and with it came many consequences. First off Old European Empires were broken up and Fifteen new nations were formed. This was a dramatic change. And another consequence of the war, and probably the most severe was that it left these gaps in the governments of some of these countries where Totalitarian Regimes could rise to power. .
In Germany, England and France made them sign the Treaty of Versailles. The terms of this treaty were that: A) They had to take sole blame for the war B) Pay 30 Billion Dollars in War Reparations C) Reduce their powerful army to 100,000 and give up their elite submarines.