I don't know if this is for college, AP, or high school, so I'll try to give you a framework to help you answer the question
Compare = Similarities
Contrast = Differences
Note the similarities and differences throughout. Then analyze those differences and similarities to explain why they're similar or different.
1) List the members of the alliance groups for
a) World War 1--Allies and Central Powers
b) World War 2--Allies and Axis Powers
Keep an eye on: Italy, Japan, and the United States
2) What type of governments did the members have?
democracies, absolue monarchies, fascist, totalitarian
3) Balance of power considerations?
4) Geographical considerations?