Identify three causes of World War I.

• A. Nationalism, militarism, alliance systems
• B. Economic sanctions, isolationism, and democracy
• C. Environmental disaster, disease, and famine
• D. Space exploration, internet, and aviation

Answer: (A)

Three forces shaped the lead-up to World War I: nationalism, militarism, and alliance systems. Nationalism fueled intense pride and rivalries among nations and ethnic groups, pushing states to pursue their interests aggressively and to challenge rivals, which created frequent tensions and a willingness to risk conflict to prove strength or achieve national goals. Militarism amplified this by making war seem like a viable or even glorious tool of policy: growing armies, powerful weapons, and the belief that quick mobilization could decide outcomes encouraged leaders to prepare for and expect conflict rather than avoid it. Alliance systems then transformed a regional dispute into a broader catastrophe: binding commitments meant that an attack on one country dragged its partners into war, turning a localized crisis into a continental and eventually global confrontation as powers honored their promises.

These ideas together explain why a single incident could escalate so rapidly. When the Archduke’s assassination occurred, the existing nationalism, the pressure of military build-up, and the obligating alliances all pushed major powers toward mobilization and intervention, pulling in multiple nations and widening the conflict.

Other choices don’t capture these root drivers. Economic sanctions, isolationism, and democracy describe policy tools or political forms but aren’t the broad forces that explain why nations went to war in 1914. Environmental disaster, disease, and famine are not primary triggers of World War I. Space exploration, internet, and aviation were not factors in the onset of the war.