German–Polish customs war

The German–Polish customs war was a political and economic conflict between the Second Polish Republic and the Weimar Republic, which began in June 1925 (shortly after the death of German president Friedrich Ebert from SPD) and ended officially in March 1934. The conflict began when Poland's status expired as one of the Entente's most favoured nations in trade with Germany. Berlin then decided to raise customs duty, which primarily affected the Polish coal industry, Poland's main export to Germany. In return, Warsaw also raised duty on German goods. Germany's purpose in the war was to cause a breakdown of Poland's economy and gain political concessions. They included revanchist claims to Polish territories.

In 1918, Poland gained independence after 123 years of foreign dominance. The economy of the newly created country was bad, the result of several wars fought on Polish soil between 1914 and 1921, and of many years of division between three partitioning powers. In 1919, industrial production on Polish lands fell by 70% in comparison to 1914, and the government in Warsaw had a difficult task. The country was divided into different economic and political systems, with several kinds of currency in circulation. The Baltic Sea port of the Free City of Danzig was not part of Poland.

The lands of former Congress Poland, which before 1914 had been responsible for 15% of industrial production of the Russian Empire, were cut off from eastern markets after the creation of the Soviet Union. In addition, the collapse of Austria-Hungary destroyed the 19th century economic ties of Galicia with Austria and Bohemia. Poland's closest ally, France, was far away, and trade with Paris was limited. Germany emerged as a main trade partner and market for Polish products. In 1925, 40% of Polish foreign trade was with Germany, and Poland's western, most developed provinces, the Polish part of Upper Silesia, Greater Poland and Pomerelia, were even more dependent on Germany, their powerful western neighbor. Until 1925, Polish Upper Silesia sold half of its coal to Germany; in Poland, there was little demand for the rest because industrial production in Polish territory was a fraction of what it had been; in 1921, it was a mere 35% of its 1913 level.

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