Some causes of nations joining world war 1
- Assassination of Archduke Franz Ferdinand
- Military rivalry between powerful nations
- US: the Zimmermann Telegram and the sinking of the Lusitania
- Colonies: The wish that if they fought for for their European countries they could be free, and so they join the war, making it a World War effectively
hope this helps
It is A. empires that accepted the tribute from states for protection
It was one of the first revolutions of its kind to occur non-violently, making it 'glorious'.