What countries were fighting in world war 1

- What two countries were fighting in world war 1
- What countries were fighting during world war 1
- What were the main countries fighting in world war 1
- How many countries were fighting in world war 1
- What were the 2 main countries fighting in world war 1
- Who was fighting in world war 2
- World war 1st and 2nd
- What if world war