After the Great War

Once the war was over and the peace treaties were signed, soldiers returned home to a very different world.  Choose a country:  Canada, United States, Germany, Russia, Germany, France... and describe a couple of differences that were in place post WWI compared to pre-WWI. 

The War to End All Wars...

One mandate of the Paris Peace Conference was to make the Great War the "war to end all wars".  As there was a Second World War, obviously it was not successful.  What role to you think the Peace Treaty had in continuing tensions rather than eliminating them?

The 2 Fronts of WWI

There were mainly two fronts where World War One was fought.  It is fair to say that the war on the Western Front was very different compared to the war on the Eastern Front.  What would be at least 2 differences between  these two wars?