History, The German Threat

Meanwhile, Poland had been in the throes of an almost continuous financial crisis. General instability and confusion led to frequent changes of cabinet. Following a coup led by Jozef Pilsudski in 1926, Ignacy Moscicki was installed as president; Pilsudski, as minister of war, gradually acquired complete control over the government in the late 1920s and early 1930s. In 1935 a new constitution was adopted formalizing his authoritarian regime. Pilsudski survived the inauguration of the new system by less than a month, and was succeeded by General Edward Smigly-Rydz.

The triumph of National Socialism (Nazism) in Germany and the expansionist policy of German dictator Adolf Hitler in the late 1930s posed grave dangers to Polish security. After the Munich Pact and the ensuing destruction of the Czechoslovak state in March 1939, Poland, which had received about 1,036 sq km (about 400 sq mi) of Czech territory in the Munich settlement, became the next major target of German diplomacy. This development took the form of German demands, delivered late in March, that Poland consent to the cession of Danzig to Germany and yield important rights in the Polish corridor. Polish rejection of these demands was followed, on March 31, by an Anglo-French pledge of aid to Poland in the event of German aggression. On April 28, Hitler renounced the German-Polish nonaggression treaty. On September 1, 1939, Germany attacked Poland after signing a pact with the USSR, an act that marked the outbreak of World War II.