Between 1919 and 1939, peace in Europe weakened as radical ideologies rejected compromise, celebrated force, and convinced many leaders that temporary concessions could prevent another continental war.

The Interwar Political Climate

After World War I, many Europeans were disillusioned with parliamentary politics, social conflict, and the apparent weakness of liberal governments. Some feared communist revolution; others believed their nations had been humiliated and needed renewal. In this atmosphere, radical movements gained support by promising order, unity, and decisive action.

• They attacked pluralism, party competition, and compromise.

• They claimed the nation, not the individual, was the highest political value.

• They treated international agreements as obstacles rather than protections.

This mattered because the interwar crisis was not only diplomatic. It was also ideological: powerful movements increasingly rejected the values of democracy, peaceful negotiation, and legal restraint.

Fascism and the Rejection of Democracy

Fascism as a Revolutionary Right-Wing Ideology

Fascism became the clearest challenge to liberal democracy in the interwar years.

Fascist movements presented politics as a struggle between strength and weakness rather than negotiation and law. They praised discipline, militarism, youth, and sacrifice. In practice, fascist regimes destroyed opposition, used propaganda, and demanded loyalty to the state and leader.

• In Italy, Benito Mussolini portrayed fascism as the cure for disorder and national decline.

• In Germany, Adolf Hitler fused fascism with a far more radical racial worldview and a determination to reshape Europe.

Because fascism celebrated war as a test of national vitality, it weakened the habits of diplomacy. A system based on compromise could not easily restrain movements that viewed compromise as surrender.

Extreme Nationalism

Interwar extreme nationalism went beyond ordinary patriotism. It insisted that the nation had absolute claims over territory, culture, and loyalty. National honor became more important than international law.

• Fascist leaders promised to revise borders and treaties they described as unjust.

• Germany sought to overturn restrictions and unite all Germans under one state.

• Italy pursued imperial expansion to prove its status as a great power.

This nationalism turned grievances into aggressive foreign policy. Instead of accepting limits, expansionist states argued that national rebirth required action. The result was a Europe in which some governments increasingly treated conquest as legitimate.

Racist Ideologies and Expansion

The most dangerous interwar ideology was the Nazi belief in a racial hierarchy. Nazi thought claimed that history was driven by conflict among races and that the German people had to secure their future through purification and expansion. Anti-Semitism was central, not secondary, to this worldview.

Racist ideology had two major consequences. First, it justified exclusion and persecution within the state by identifying supposed internal enemies. Second, it justified expansion abroad by portraying other peoples, especially Slavs and Jews, as inferior or threatening.

This logic pushed policy beyond normal power politics. Hitler did not merely want diplomatic revision; he envisioned a racial empire in eastern Europe. The idea of Lebensraum, or living space, linked nationalism to racial conquest. Land, resources, and domination over supposedly inferior populations were presented as necessities for Germany’s survival. That made war more likely because such goals could not be satisfied by limited concessions.

Appeasement and the Failure to Stop Aggression

Many British and French leaders adopted appeasement as their main response to revisionist powers.

Appeasement was not simply cowardice. It reflected the deep trauma of World War I, economic weakness, military unpreparedness, and the belief that some demands of the dictators might be negotiable. Many policymakers hoped that if limited claims were satisfied, the larger peace could be preserved.

• Britain and France did not decisively resist German rearmament.

• They failed to stop the remilitarization of the Rhineland.

Photograph of German troops marching into the Rhineland during the 1936 reoccupation. As a primary-source visual, it underscores how Nazi foreign policy translated ideology into action and how limited responses by other powers encouraged further escalation. Source

Political map of Europe in March 1936 marking the remilitarization of the Rhineland in the broader interwar timeline. The map helps visualize why this move mattered strategically: it reduced France’s security buffer and signaled that treaty limits could be violated without immediate consequences. Source

• They accepted the Anschluss with Austria and then the Munich Agreement, which gave Germany the Sudetenland from Czechoslovakia.

Each concession had serious consequences. It weakened confidence in collective security, discouraged smaller states, and convinced dictators that the democracies lacked resolve. Appeasement therefore did not calm aggression; it reduced the costs of aggressive behavior.

Why Appeasement Failed

Appeasement became especially dangerous because it operated against leaders driven by ideological goals. Fascist and Nazi regimes did not interpret concessions as steps toward mutual settlement. They read them as proof that democracies were divided, exhausted, and unwilling to fight.

• Fascism glorified force and despised democratic caution.

• Extreme nationalism transformed grievances into demands for expansion.

• Racist ideologies made compromise difficult by framing conquest as a necessity.

• Appeasement gave aggressive states time, confidence, and strategic advantage.

By 1939, the crisis had moved beyond treaty revision. The ideological foundations of fascist foreign policy made a wider war increasingly likely, and the invasion of Poland showed that appeasement had failed to preserve peace.