Hitler, cheerful with the successful annexation of the Sudetes and the annexation of Austria to the Reich, he decided not to stop his expansion, conducted in the spirit of uniting all “Germanic” lands within the limits of the self-created “The Thousand-Year Reich”. Another goal of his activities was the Free City of Gdańsk and Pomerania, which he considered to be an integral part of the German Reich, seized from the German people under “the Versailles dictate”. These ambitions became the main cause of the outbreak of the war between Poland and the Third Reich.
At first, Germany did not pursue an aggressive policy towards Poland, believing in the annexation of the desired territories without firing a shot, as was the case with Austria or Czechoslovakia. Hitler was counting on it, that Poles, having understood the intentions of German diplomats, intimidated by the unspoken threat of war, they will give Gdańsk back to the Germans immediately. He also had hope, that by resolving the matter with Poland in a peaceful manner, in the form of a non-imposed settlement, makes the Russians assume, that they should see the enemy in Poland, which could dismiss the threat of a possible war between the Reich and the USSR until the time, when Germany was fully ready for it.
For this purpose, in October 1938 year, German Minister of Foreign Affairs, Joachim von Ribbentrop, during a conversation with Ambassador Józef Lipski, first addressed Poland with a proposal to connect Gdańsk to the Third Reich and to build an extraterritorial motorway and railway through Polish Pomerania. He also suggested Poland joining the Anti-Comintern Pact. In return, Poland would receive German guarantees by extending the non-aggression pact for further 25 years
Hitler was counting, that Poles, wanting to avert the threat of German aggression, they will without hesitation decide to accept the conditions imposed on them. However, the Polish side responded clearly ? there is no such solution. Hitler was already making predictions then, that he would not succeed in his plan and he would not go as easily with Poland as with Austria, or Czechoslovakia.
Hitler repeated his grievances 4 January 1939, during the conversation with Józef Beck and they were no longer propositions, but demands, which Poland categorically rejected. The German leader began to realize, that the nationalist attitude of Poles, which ruled out any submission to another country, adopting the words PRosjaiłsudski as the motto “To be defeated and not to be victorious”, eliminated the possibility of joining Gdańsk to the Reich by peaceful means.
In response to Polish objection, Hitler 28 April, he gave a speech in the Reichstag, in which he denounced the Polish-German non-aggression treaty with 1934 year. The reaction of the Polish side to such actions was the speech of Józef Beck on 5 May, in which he clearly and publicly made the Germans understand, that the Germans would take over Gdańsk only after Poland's troubles. “I have to ask myself a question, what exactly is it about” – the Polish minister spoke from the parliamentary rostrum – “or for the freedom of the German population of Gdańsk, which is not at risk, or about prestigious matters, or to push Poland away from the Baltic Sea, Poland cannot be pushed away from. (…) We in Poland do not know the concept of peace at any cost. There is only one thing in people's lives, nations and states, which is priceless: that thing is honor”.
Hitler definitely came to the conclusion, that Gdańsk would only receive by force. He did not take any official actions to convince the Polish side, for he knew, that they wouldn't get anywhere. He began to prepare for an armed intervention.