What effect did military alliances have on WWI?

• A. Reduced war
• B. Kept states neutral
• C. Drew multiple countries into conflict due to mutual defense promises
• D. Made diplomacy unnecessary

Answer: (C)

Mutual defense commitments pull nations into war because states are bound to come to each other’s aid. In World War I, the alliance system meant that when Austria-Hungary attacked Serbia, Germany pledged support to Austria-Hungary, and Russia moved to defend Serbia. France aligned with Russia, and Britain joined to uphold balance of power and treaties, drawing in more countries as each obligation was triggered. What might have stayed a regional conflict expanded into a world war as armies and fronts multiplied, all because allies promised to fight for one another.