German–Polish customs war
[note 1] Berlin then decided to raise customs duty, which primarily affected the Polish coal industry, Poland's main export to Germany.
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.
The lands of former Congress Poland, which before 1914 had been responsible for 15% of industrial production of the Russian Empire,[4] were cut off from eastern markets after the creation of the Soviet Union.
[5][6] In the early interwar period, in Germany, the Second Polish Republic was regarded a "temporary state" ("Saisonstaat") and tensions between the two nations were high.
The German-Polish border was never officially accepted by Germany and from the start of 1919 German foreign policy aimed at revising the Versailles Treaty and acquiring once more Polish territories.
The population in the territories of Silesia and parts of Poland of the former Prussian partition, a significant minority of them ethnic Germans, became Polish citizens.
[14] Helmut Lippelt writes that Germany used the existence of the German minority in Poland for political purposes and as part of its revanchist demands, prompting Polish countermeasures.
In response to a British proposal, Stresemann wrote to the German ambassador in London, "[A] final and lasting recapitalization of Poland must be delayed until the country is ripe for a settlement of the border according to our wishes and until our own position is sufficiently strong".
According to Stresemann's letter, there was to be no settlement "until [Poland's] economic and financial distress ha[d] reached an extreme stage and reduced the entire Polish body politic to a state of powerlessness".
With her blood her strength will flow away as well, and finally her independence"[19] In the immediate post-World War I period, trade between both nations was regulated by the Treaty of Versailles and by the Geneva Convention on Upper Silesia (1922).
The Treaty of Versailles required Germany to give most favoured nation status unilaterally to all Triple Entente countries as well as to its newly created eastern neighbors.
[22] While divergent terms were settled in bilateral treaties between Poland and France, Czechoslovakia, Hungary and Greece, the taxes on other imports were raised 100%.
[23] In the negotiations of early 1925, Germany tried to buy time by raising trade and minority issues, such as the "Optanten" problem, liquidation measures and settlement rights; on 15 June, the relevant clauses of the treaty would expire.
Germany demanded Poland to give up undisputed rights from the Treaty of Versailles and to revise the Vienna Convention, closed six months earlier.
[24] In January 1925, when Germany recovered its trade policy sovereignty,[25] all purchases of Polish coal were stopped[26] and customs duties raised on all Polish-made products.
[27] When Polish delegations tried to reach a peaceful understanding with Germany on 10 December 1926, Stresemann rejected the talks by saying there would be no normalization of German-Polish relations until the "border problems" were resolved.
Poland found new trade partners, making their economy less dependent on Germany overall, a domestic modernization program was successfully accelerated and the port of Gdynia enjoyed dynamic growth.
