War breaks out in Europe

[DIESEL]

War breaks out in Europe

In Europe, Germany and Italy were becoming bolder. In March 1938 Germany annexed Austria, again provoking little response from other European powers.[29] Encouraged, Hitler began pressing German claims on the Sudetenland, an area of Czechoslovakia with a predominantly ethnic German population; France and Britain conceded this territory to him, against the wishes of the Czechoslovak government, in exchange for a promise of no further territorial demands.[30] However, soon after that, Germany and Italy forced Czechoslovakia to cede additional territory to Hungary and Poland. In March 1939 Germany invaded the rump of Czechoslovakia and subsequently split it into the German Protectorate of Bohemia and Moravia and the pro-German Slovak Republic.

Alarmed, and with Hitler making further demands on Danzig, France and Britain guaranteed their support for Polish independence; when Italy conquered Albania in April 1939, the same guarantee was extended to Romania and Greece.[31] Shortly after the Franco-British pledge to Poland, Germany and Italy formalized their own alliance with the Pact of Steel.[32]
A German Heinkel He 111 bombing Warsaw in 1939

In August 1939 Germany and the Soviet Union signed a non-aggression pact.[33] This treaty included a secret protocol to split Poland and Eastern Europe into separate spheres of influence.[34]
Soviet and German officers in Poland, September 1939.

On September 1, 1939, Adolf Hitler launched his invasion of Poland and World War II broke out. France, Britain, and the countries of the Commonwealth declared war on Germany but provided little military support to Poland other than a small French attack into the Saarland.[35] On September 17, 1939, after signing an armistice with Japan, the Soviets launched their own invasion of Poland.[36] By early October, the campaign ended with division of Poland among Germany, the Soviet Union, Lithuania and Slovakia,[37] although officially Poland never surrendered.

At the same time as the battle in Poland, Japan launched its first attack against Changsha, a strategically important Chinese city, but was repulsed by early October.[38]

Following the invasion of Poland, the Soviet Union began moving troops into the Baltic States. Finnish resistance to similar pressure by the Soviet Union in late November led to the four-month Winter War, ending with Finnish concessions.[39] France and the United Kingdom, treating the Soviet attack on Finland as tantamount to entering the war on the side of the Germans, responded to the Soviet invasion by supporting its expulsion from the League of Nations. Though China had the authority to veto such an action, it was unwilling to alienate itself from either the Western powers or the Soviet Union and instead abstained. The Soviet Union was displeased by this course of action and as a result suspended all military aid to China.[40] By June 1940, the Soviet Armed Forces completed the occupation of the Baltic States.[41]
German troops in Paris after the fall of France.

In Western Europe, British troops deployed to the Continent, but neither Germany nor the Allies launched direct attacks on the other. The Soviet Union and Germany entered a trade pact in February of 1940, pursuant to which the Soviets received German military and industrial equipment in exchange for supplying raw materials to Germany to help circumvent a British blockade.[42] In April, Germany invaded Denmark and Norway to secure shipments of iron-ore from Sweden which the allies would try to disrupt. Denmark immediately capitulated, and despite Allied support, Norway was conquered within two months.[43] British discontent over the Norwegian campaign led to the replacement of Prime Minister Neville Chamberlain by Winston Churchill on May 10, 1940.[44]