What were the main causes of World War I, and how did alliances contribute to a global conflict?

• A. Only economic rivalries mattered; alliances had no effect.
• B. Nationalism, imperialism, militarism, and entangling alliances; alliances pulled many nations into war after a single crisis.
• C. The war was caused by a single country acting alone.
• D. Alliances prevented the spread of war.

Answer: (B)

A single crisis in the Balkans didn’t cause a war by itself; a network of powerful forces did. The main idea here is that a mix of nationalism, imperialism, militarism, and entangling alliances created a situation where many nations were drawn into a conflict after one spark. Nationalism pushed groups and nations to assert their interests aggressively, sometimes seeking independence or dominance. Imperialism fed competition among the great powers as they vied for colonies and global influence. Militarism raised the mindset and preparedness for war, making sides ready to mobilize quickly and decisively. The most decisive piece, though, is the alliance system itself: promises of aid and defense bound countries to support one another, so when the crisis occurred, those commitments pulled a broad, interlinked set of powers into war, turning a regional dispute into a world-wide conflict.