I voted for the last choice. I believe the ideaologies of the different governments were made to clash at some point. Versailles was a focal point and nothing more. You have to remember the tenants of the Nazis, the Aryan Superrace doctrine that at some point would involve the rest of Europe. Same with Mussolini and to an extent Stalin.
Versailles and the Depression and all the other economic hardships and hatreds allowed these governments to be hostile. It was inevitable.
It's a chicken and egg story, really. I believe the rising of the NSDAP only occurred after the economic climate went down hill. So the depression really helped Hitler into the saddle.