Did armies or treaties draw Europe’s borders after WWI?

The short answer

• The method Versailles set. The Treaty of Versailles, weighed in Chapter 14, settled Germany’s frontiers and set the method every other treaty followed. That method ran from the Covenant of the League of Nations, its founding charter, to reparations and new borders. This chapter follows that method into central and eastern Europe, where the defeated states were smaller and weaker, the ethnic map was far more tangled, and the victors’ promises to their own allies had to be paid for with the losers’ territory.
• Empires that collapsed into a vacuum. Three empires fell within twenty months, from the Tsar’s abdication in March 1917 to the collapse of Austria-Hungary and Germany in November 1918, and the fourth, the Ottoman, was being dismembered. When the armistice was signed nobody controlled the lands between Germany and Russia, and national councils proclaimed new states in Prague, Zagreb, Warsaw and the Baltic capitals before the peacemakers met. Where two new states claimed the same land, as Poland and Lithuania did over Vilnius, armies decided, so the conference often ratified facts on the ground.
• Promises made in wartime. The victors had bought allies with promises that the peace now had to honour. Italy had been offered South Tyrol, Istria and much of Dalmatia in the Treaty of London of 1915, Romania had been promised Transylvania in 1916, and Britain had promised Arab independence, a Jewish national home in Palestine and a division of the Middle East with France. Where promises clashed, the strongest claimant usually won, and the losers of these bargains, from Italian nationalists to Arab leaders, joined the defeated states in resenting the settlement.
• The Bolshevik challenge. Soviet Russia was excluded from the peace conference and treated as a danger to be contained, while Lenin expected revolution to spread westward. That fear shaped the settlement, because the victors backed strong new states on Russia’s border, accepted Romania’s annexation of Bessarabia and tolerated Poland’s eastward expansion. In 1919 short-lived Soviet republics in Hungary and Bavaria made the danger look real. The new map was designed to contain Moscow as much as Berlin, and Moscow treated it as a hostile wall.

What it changed

Guardians and revisionists. The map of 1923 divided Europe into states that wanted to keep the settlement and states that wanted to overturn it. France allied with Poland in 1921 and went on to sign treaties with the Little Entente of Czechoslovakia, Romania and Yugoslavia, while Germany, Hungary and Bulgaria demanded revision and Fascist Italy, a disappointed victor, increasingly joined them. The guardians were mostly new, small and divided among themselves, while the revisionists included the strongest economy on the continent, so the balance of the map favoured those who wanted to redraw it.

Minorities as pretexts. The new map made national minorities a standing source of conflict. Some 25 to 30 million Europeans lived in someone else’s nation-state, and treaties supervised by the League promised them schools in their own language and equality before the law. The League’s procedures were slow, many complaints were set aside, and governments in Warsaw, Bucharest and Belgrade pressed assimilation. In the 1930s Nazi Germany used the grievances of German minorities in Czechoslovakia and Poland as pretexts for breaking the settlement apart, turning a promise of protection into a weapon against the states that had signed it.

Hyperinflation and the radical right. The Ruhr crisis drove German inflation out of control, until in November 1923 a lifetime’s savings could not buy a loaf of bread. That same month Adolf Hitler, leader of a small Munich party, tried to seize power in the Beer Hall Putsch, an armed coup launched from a Munich beer hall, convinced the republic was about to fall. He failed and went to prison, but the year of occupation and hyperinflation left millions of Germans linking the treaty, the republic and ruin in a single memory.

From Lausanne to the next war. The wars of 1919–1922 hardened the belief that stable frontiers required nations of a single people, and the Lausanne exchange gave that belief international approval. Winston Churchill cited it in 1944 to defend expelling Germans from the lands Poland would gain, a policy carried out in 1945 after Nazi Germany’s war of conquest and occupation. The next war began in 1939 over Danzig, the German port the peace made a Free City, and the Polish Corridor that cut East Prussia off from Germany, fault lines drawn in these years.