World War I (1914–1918)
1. Nationalism: High Importance (Structural Cause)
Nationalism was arguably the most important long-term cause of WWI.
Balkan Nationalism ("Powder Keg of Europe"): Slavic nationalism (especially Serbian) wanted to break free from Austria-Hungary and unite with Russia. The assassination of Archduke Franz Ferdinand by a Bosnian Serb nationalist (Gavrilo Princip) was the immediate trigger.
Unifying & Destabilizing: Nationalism unified Germany (1871) and Italy, but destabilized the multi-ethnic empires (Austria-Hungary, Ottoman Empire). These empires feared breakup, making them aggressive.
Competitive Nationalism: French revanchism (wanting back Alsace-Lorraine), Pan-Slavism (Russia protecting Slavs), and German militarism (national pride in army/navy) created hostile alliances.
Verdict: Essential as a long-term fuse. Without rising ethnic nationalism, the assassination might have been a minor crisis, not a world war.
2. Selfish Ambition: Moderate-High Importance (Immediate & Strategic)
Selfish ambition operated at the leader and state level in July 1914.
Austria-Hungary's Ambition: Used the assassination as a pretext to crush Serbia once and for all. This was a calculated, power-seeking gamble.
Germany's "Blank Check": Kaiser Wilhelm II and his generals selfishly encouraged Austria to act fast, hoping for a quick war now before Russia modernized its army. They deliberately escalated.
Russia & France's Ambition: Both saw the crisis as a chance to weaken Germany/Austria. Russia mobilized not just to defend Serbia but to assert itself as the Balkan protector.
Leaders' Hubris: The Kaiser, Czar Nicholas II, and Austro-Hungarian leaders showed reckless, ego-driven decision-making.
Verdict: Crucial as the trigger mechanism. The willingness to risk general war for strategic gain turned nationalism into violence. But absent nationalist pressures, ambition might have found other outlets (e.g., colonial wars).
WWI Summary: Nationalism = the deep structural cause. Selfish ambition = the proximate cause that lit the fuse.
World War II (1939–1945)
1. Nationalism: High Importance, but Different Form
Nationalism in WWII was even more toxic, racialized, and expansionist.
German Nationalism (Nazi version): Based on racial superiority (Aryan master race), Lebensraum (living space in the East), and reversal of Versailles. Hitler mobilized mass, violent nationalism.
Japanese Nationalism: Ultra-nationalist military factions pushed "Asia for Asians" (really Japan ruling Asia), racial superiority, and a divine emperor. Led to invasion of Manchuria (1931) and China (1937).
Italian Nationalism: Mussolini's rhetoric of a "new Roman Empire" drove invasion of Ethiopia (1935) and Albania (1939).
Verdict: Essential driving ideology. Unlike WWI, nationalism in WWII was openly genocidal and imperial. Without Nazi racial nationalism, no Holocaust; without Japanese ultra-nationalism, no Pacific war.
2. Selfish Ambition: Very High Importance (Personal & State)
Selfish ambition in WWII was personified in dictators and their inner circles.
Hitler's personal ambition: Unbounded desire for conquest, glory, and racial purification. He defied his own generals repeatedly (e.g., invading Poland against military advice, breaking the Nazi-Soviet pact).
Mussolini's ego: Invaded Greece and Egypt to match Hitler's successes, overstretching Axis forces.
Tojo & Japanese militarists: Selfish ambition for resources (oil, rubber) and regional hegemony, leading to Pearl Harbor.
Stalin's ambition: Though allied against Hitler, Stalin's 1939 pact with Germany (carving up Poland) was nakedly self-interested.
Verdict: Indispensable. Hitler's personal drive was the central cause of the European war. Without his selfish ambition, Germany's rearmament might have remained defensive. Japan's military clique similarly chose war over diplomacy.
WWII Summary: Selfish ambition (especially Hitler's) = the primary, active cause. Nationalism = the fuel that made ambition popular and soldiers willing to die/fight.
Comparative Table: Importance Rating (1–10)
CauseWorld War IWorld War IINotesNationalism9/10 (structural)8/10 (ideological)WWI: Balkan trigger + imperial rivalries. WWII: racial/expansionist nationalism.Selfish Ambition7/10 (leaders gambled)10/10 (dictators drove it)Hitler's ambition unique in scale & recklessness.
Final Conclusion
For WWI: Nationalism was the deeper, necessary condition (without it, no assassination crisis). Selfish ambition was the sufficient condition (without leaders choosing war, crisis could have been resolved).
For WWII: Selfish ambition, specifically Hitler's, was the primary cause. Nationalism gave him the mass movement and justification, but no other leader at the time would have started a war of extermination on that scale without his maniacal ambition.