It ended WW1. I'd say that's pretty significant.
The short term effects of the Treaty of Versailles is that Germany had to accept guilt for starting the war, was forced to pay Allies reparations, lost land, and had to reduce the size of it military. The League of Nations was created to settle disputes between countries before military conflict. By about 1919, Germany was no longer one of the most economically advanced nations in the world because of this.