What Actually Happened To 11 Major Countries Between The World Wars

WWI: Not an independent nation, but much of the fighting on the eastern front took place in Poland 

WWII: Allies (defeated in 1939)

What happened in between: The historical Polish-Lithuanian Commonwealth ceased to exist at the turn of the 19th century after it was carved up between Prussia, Russia, and Austria-Hungary. The Treaty of Versailles resurrected Poland in 1919, but largely left the infant Second Republic to fend for itself. Poland fought a series of border conflicts with its neighbors, including a desperate struggle against the Soviet Union in 1920. The borders of the republic were finally settled in 1922.

Poland's economic development was stunted by limited trade due to its frosty relations with Weimar Germany and the Soviet Union. The republic's troubles were compounded by social unrest caused by tensions between Poles and the sizeable population of minorities. Poland's shaky democratically elected government was overthrown by a 1926 coup headed by the hero of the Soviet conflict, Józef Piłsudski. 

He was the dominant political figure in interwar Poland, though he only officially led the country from 1918 to 1922 and served as Prime Minister from 1926 to '28. Piłsudski has sometimes been described as a quasi-dictator. Toward the end of his life, he concentrated on strengthening the army and relieving Poland's dire geopolitical situation. He secured nonaggression pacts with both the USSR and Germany in 1932 and 1934, respectively. 

Poland's fate was pretty much sealed with the von Ribbentrop-Molotov Pact of 1939. Caught hopelessly between two powerful enemies, the country was once again carved up between Germany and Russia in 1939. Exiled Polish pilots and soldiers fought on for the Allies after Poland capitulated. 

WWI: Triple Alliance (pre-war) Allies (from 1915, victorious)

WWII: Axis (defeated)

What happened in between: Pre-1914, Italy was a somewhat noncommittal member of the Triple Alliance alongside Germany and Austria-Hungary. When WWI broke out, Italy remained on the sidelines until lured to the Allied side with substantial promises of territory. After years of fruitless combat, mostly in the mountains, Italy was dismayed to learn that the British and French would not honor the promises they made. 

The immediate postwar years were consumed with social unrest and conflict between fascists and socialists, which culminated in Benito Mussolini's march on Rome to seize power in 1922. He moved quickly to shore up fascist rule by imprisoning political opponents and imposing tight restrictions on the media.

Although Italy was initially an opponent of Hitler, German recognition of the country's ambitions in East Africa - and a shared goal to support Francisco Franco in Spain - brought the two nations together. When Germany invaded France in 1940, Mussolini sensed an easy victory and threw in with the Third Reich. Ultimately, the Italians proved to be more of a hindrance than a help to the Axis.

WWI: Neutral 

WWII: Neutral (Axis aligned)

What happened in between: The deadly influenza outbreak in 1918 that saw more than 50 million people perish was colloquially known as the "Spanish Flu," but the virus did not originate in Spain at all. The reason for the association is that the Spanish press wasn't under the same wartime restrictions as other European nations, so it reported freely on the outbreak, leading to the misnomer. Spain wisely stayed out of WWI entirely, but was still embroiled in a lengthy colonial conflict in Morocco.

A 1923 coup headed by Miguel de Rivera saw Spain fall under a dictatorship until 1930. The Second Spanish Republic proved to be short-lived, as one of de Rivera's protégés, Francisco Franco, was instrumental in a military conspiracy to overthrow the Republic in 1936. The three-year Spanish Civil War ended with the victory of Franco's forces in April 1939. Although aided by Italy and Germany during the Civil War, Franco's Spain did not join the Axis Powers in WWII. The closest Spain came to entering the conflict was a meeting between Franco and Adolf Hitler in October 1940, but the Spanish dictator's demands were too high. Franco remained in power until the 1970s.

WWI: Central Powers (defeated)

WWII: Axis (absorbed by Germany in 1938, defeated)

What happened in between: The union between Austria and Hungary was dissolved in the final days of WWI. In the peace settlement, Austria was left as a small landlocked republic with unfriendly neighbors. As the new nation struggled to support itself, violent clashes between left- and right-wing paramilitary groups broke out. These culminated in a deadly riot in Vienna in 1927 when three far-right militia members were acquitted of murder.

As Austria struggled in the Great Depression, the First Austrian Republic collapsed after a short but intense civil war. The republic was replaced by a one-party fascist state, the Federal State of Austria in 1934. A Nazi coup, which claimed the life of the chancellor, was thwarted in July 1934 thanks to Italy's support. Benito Mussolini threatened war with Germany if the Third Reich attempted to force a union with Austria.

This was ultimately only delaying the inevitable. As German and Italian relations warmed, the main obstacle to the formal union of Germany and Austria, the Anschluss, was removed. Austria was absorbed into the Third Reich in 1938.

WWI: Allies (victorious)

WWII: Allies (victorious)

What happened in between: Britain's interwar years were characterized by key political and social reforms at home, managing an empire that reached its greatest extent in 1919 and managing an increasingly tense situation in Europe. Universal suffrage, the expansion of the welfare state, and a massive housing program helped dampen the revolutionary zeal sweeping across the postwar world. 

The British Empire reached its greatest extent in 1919 when the Treaty of Versailles handed over formerly German and Ottoman colonies in Africa and the Middle East. Ireland broke away from Britain first as a dominion in 1922; it fully severed ties in 1937. Other British dominions achieved de facto independence in 1931, while nationalist sentiment rose in India as the independence efforts gathered pace. It wouldn't be until after WWII, however, that India's aim would be realized.

Britain's policy toward Germany in the initial postwar years was more conciliatory than France's, as Britain wanted to see Germany revived as a strong trade partner. Disarmament treaties were well-intentioned but lacked teeth, as the horrors of the First World War made the British government reluctant to pursue a more assertive foreign policy.

The response in the late 1930s to Hitler's increasingly outrageous demands was to appease rather than confront. The policy was vilified by future generations, but Neville Chamberlain's attempts to maintain peace were broadly supported by the British public at the time. The Danzig Crisis was the last straw. 

WWI: Allies (from 1915, victorious)

WWII: Axis Powers (defeated)

What happened in between: Japan sided with the Allies in WWI, honoring an earlier alliance with Britain. It came through the conflict without significant losses and gained possession of Germany's Asian and Pacific colonies. Japan's relations with the Western World soured when a proposal to include a racial equality clause in the Treaty of Versailles was rejected. Rising food prices in 1918 led to widespread unrest and the collapse of the government. 

The early Taisho period hinted at a new course for Japan - toward universal suffrage, great personal freedoms, and a less aggressive foreign policy. Progress was stunted by the disastrous 1923 earthquake and the passage of the highly restrictive Peace Preservation Law. The worldwide economic difficulties of the Great Depression saw the military take control. The Mukden Incident was instigated by the army as a pretext to invade Manchuria in 1931. The widely condemned aggression in China saw Japan withdraw from the League of Nations in March 1933.

Japan's interwar period ended in 1937 with the full-scale invasion of China and the beginning of the Second Sino-Japanese War.