Now, that is a subject I never heard about. Which was the state of relations between Poland and Nazi Germany in the interwar period and how did they evolve under the Nazi regime until the outbreak of WW2?
Under the Weimar Republic, German-Polish relations were in a state of flux. Germany would seek to play Lithuania and Poland off against one another, alternately supporting one, then the other, in the hope of keeping both too pre-occupied to interfere in East Prussia. Eventually, however, the situation with Poland became problematic enough that Germany, in an attempt to win political and territorial concessions, instituted a
customs war with its neighbour. This raised tariffs on Poland's primary export, coal, having a deleterious effect on the Polish economy. Poland retaliated by raising tariffs on German goods, but Germany had by far the stronger economy, with a diversified export market that was strong enough to scupper a large proposed British loan to Poland.
Poland sought defence from Germany, and therefore formed a close
alliance with France. Germany responded with a secret military
agreement with the USSR. French diplomacy in the immediate post-war period was designed to keep Germany weak through the use of
multilateral and bilateral defence treaties, such as
the Little Entente. The mood in France became more and more pacifistic, however, and led directly to the
Locarno Treaty with Germany.
There were many aspects to this treaty, including a debt-cancellation deal with Poland, but the issue of primary importance to both the French and Polish governments - and the German one - was the ratification of the territorial rearrangements in the Treaty of Versailles. That is, Germany agreed to recognise, and not attempt to regain, the territory it lost at the end of WWI... In the west. In the east and north, Germany was given a free hand. France did not demand, much to Poland's disgust, that Germany recognise the borders with Poland, Lithuania, Denmark, and Czechoslovakia. This opened up the distinct possibility that Germany may seek to make good on revanchist claims on those states in the future, and that France might let them.
This treaty, while securing France from a then non-existent German threat, did so at the expense of cutting loose all of France's allies in Eastern Europe, especially Poland. The Poles, rightly furious, sought their security by pursuing a closer relationship with Germany, recognising that the divided state was both less threatening than, and more likely to cause problems, than the USSR. By this time, however, the Weimar Republic was suffering from the
collapse of the investment bubble brought about by the Great Depression. So the Poles were forced to stay pro-French by the lack of options. Weimar was also in a state of constant political flux, with the very real threat of a military coup or communist takeover.
Enter Hitler. Hitler was appointed Chancellor on 30 January, 1933, and immediately took a different foreign policy approach. The previous Weimar cooperation with the USSR was abandoned, freeing Poland from fear of a two-front war between with the two pariah states. Hitler saw his primary foreign
and domestic policy initiative as defending Germany from communism; this image of an anti-communist strongman was why the nationalists had called him to power in the first place. As such, the USSR was the most obvious external threat, and the KPD the most prominent internal one. Hitler's anti-communism and anti-Semitism was very attractive to
Second Commonwealth, itself a very anti-communist and anti-Semitic state.
The Camp of National Unity didn't take charge until 1937, but previous governments were almost as authoritarian; like Hitler, Mussolini was their model.
This new ideological similarity, and the change in Germany's stance towards the USSR, opened up the possibility of a
rapprochement between the two powers. Hitler saw Poland as both a buffer to, and potential springboard and ally for an assault on, the USSR. He almost immediately began peppering his speeches with pro-Polish comments, even though he'd gladly used anti-Polonism to win support in Prussia and Bavaraia before he came to power (for the record, these are bloody hard to find online, at least for an English-speaker. They're probably a lot easier to find in German).
On the part of Poland, its Foreign Minister
Jozef Beck initially sort to fulfill dictator
Jozef Pilsudski's dream of an Eastern European coalition against both Germany and the USSR. He quickly, however, recognised that this was an untenable position, and signed a
Non-Aggression Pact with Germany in 1934. Beck did resist Nazi attempts, however, to enlist Poland in an anti-USSR alliance, pursued by both Hitler and his moderate nationalist Reich Minister of Foreign Affairs,
Konstantin von Neurath, due to fear that this would kill off any chance of continued agreements with France and Britain, and possibly precipitate a Soviet reaction.
This policy was pursued diligently by both Hitler and Beck, as well as Pilsudski's successor
Kazmierz Bartel from 1933-38. For what it's worth, Pilsudski's death in 1935 may have scuppered a proposal for Polish entry into a proto-
Anti-Comintern Pact; Bartel was less interested in the German alliance, preferring to keep both the USSR and Germany at arm's length. This did not stop German attempts to keep Poland onside, however, as it was seen as expedient to keep Poland out of the French orbit, even if it could not be brought into the German one; exemptions in favour of Poles were made in Germany's laws on immigrant labour, Poland was given territory in the
Munich Pact, and Hitler and Goebbels kept revanchist claims on Danzig and the Polish Corridor out of German publications, in particular
Der Sturmer.
This policy changed after the Munich Pact.
Joachim von Ribbentrop, Neurath's useless replacement, who had already destroyed the profitable relationship with China, and taken credit for the
anschluss and the Pact despite having both handled by Hermann Goering - prompting Goering to slap him in the face in front of a gleeful Goebbels in September 1938 - asked Poland if it would be willing to renegotiate the status of Danzig. Poland, correctly deducing that this would be economic suicide for Gdynia and their independent foreign trade, balked. So Ribbentrop, instead of politely changing the subject, angrily expelled all Polish Jews from the Sudetenland, an action he had absolutely zero authority to do. Most of these Jews had fled the anti-Semitism of Poland decades before; many of them were born in Czechoslovakia, and didn't speak a word of Polish.
This understandably angered Poland, which refused the Jews entry, leaving them stranded in no-man's-land between the two states; some were even stuck living on an island between the two states for a month. Eventually Poland relented, only to face another angry request from Ribbentrop for a renegotiation of Danzig's status. He was politely told to get stuffed.
Ribbentrop's Anglo-phobia, which had previously kept him out of Hitler's inner circle, had now become an asset; Hitler's exposure to Chamberlain, and the unwanted Munich Pact, had left him in utter contempt of the "little worms," and "umbrella politicians" (the umbrella is a symbol of peace in Germany). Ribbentrop's long history of denouncing everything British was now seen by the
Fuhrer as prophetic, rather than embarrassing, and he began to listen to the RAM more. Ribbentrop was already anti-Polish, and Hitler's failures to bring Poland into his orbit, as well as his newfound belief that the British and French were too cowardly to oppose him, led him inexorably towards the anti-Polish stance culminating in the outbreak of WWII.
Hitler's first ever negative opinion of Poland in public as
Fuhrer was in March 1939; over six years after he came to power. Even then, several more attempts were made to renegotiate over Danzig before Hitler expelled Polish migrant workers from eastern Germany, with Ribbentrop's backing - and over protests from
Robert Ley and
Richard Walther Darre, who recognised their necessity to German agriculture - precipitating both an economic and diplomatic crisis. Eventually, as we all know, German and Polish relations descended enough for war to break out.