Which countries fought each other in world war 1
- Which countries fought in world war 1
- Which countries fought against each other in world war 1
- Which countries fought against each other during world war 1
- Which countries fought in world war 1 and 2
- Which countries fought together in world war 1
- Who was fighting in world war 2
- Countries world war 2
- World war 1st and 2nd