The idea that Poland did not accept any German peace offers is patently false. One of Hitler's very first diplomatic agreements was the Polish-German Nonaggression Pact of January 1934. Although the Pact did gloss over the issue of Danzig and the Polish corridor, it did lead to a mild warming of Polish-German relations and a brief downplaying of Danzig in National Socialist agitprop. The Danzig issue returned in the post-Munich Pact diplomacy, but it was a pretext for Hitler to start a war, not its cause.

The Polish-German Pact did form the basis for negotiations during and after Munich. In a series of meeting in 1938 and 1939, Von Ribbentrop implied to the Polish Foreign Minister Jozef Beck and Ambassador Jozef Lipski that Germany would expand the Pact if Poland gave up Danzig and allowed for German-controlled motorways into East Prussia. In exchange for these concessions, Germany would back Poland's access to territory within Ukraine or Lithuania. The Polish responses to these overtures were naturally quite cool; after all, neither Ukraine nor Lithuania were Hitler's to give and accepting this redefined Pact would mean Poland was Germany's vassal. For their part, Anglo-French, and to a lesser extent American diplomacy was trying to stiffen Polish resolve on the Danzig issue lest it give in and present Hitler with another bloodless victory. Hitler's own post-Munich moves such as the absorption of the rump Czechoslovakian state had shown that he was a fundamentally untrustworthy diplomatic partner. This Western diplomacy was messy, but also predicated on trying to stop the outbreak of general European war. Had Poland followed suit and surrendered the corridor for other compensation, that might mean war in Eastern Europe.

Poland did not need this Western pressure to hold fast over Danzig. Realistically, Beck and the Polish foreign policy leadership had correctly ascertained that Danzig was a pretext for a general war. Von Ribbentrop's overtures were a sounding out of other hypothetical courses of action, but Hitler had more or less resolved to have an actual war over Poland by 1939. In a May 1939 meeting with his generals, the German dictator declared:

Danzig is not the objective that this is about. For us, this is about extending our Lebensraum in the east and securing a food supply, as well as solving the problem of the Baltic states. food can be supplied only from places that are sparsely populated. Using the fecundity there, thorough German cultivation will vastly increase the surpluses. There is no other possibility in sight in Europe.

Hitler would likewise claim that he feared some foolish diplomatic intervention over Danzig in other meetings with his military chiefs and diplomats. All of this led to Germany's unilateral abrogation of the Polish-German Nonaggression Pact in April 1939 and preparations for war.

Although the idea that Poland unwisely stood in the way of peace was a prominent feature of Nazi propaganda justifying the war and remains a staple of neonazi apologia for Hitler, there really was no realistic option for Poland in 1939. Beck had signaled a willingness to compromise to von Ribbentrop in their negotiations, but German demands were often quite excessive . When the Italian Foreign Minister Galeazzo Ciano visited the Salzburg in August 1939, he wrote in his diary:

The decision to fight is implacable. [Ribbentrop] rejects any solution which might give satisfaction to Germany and avert the struggle. I am certain that even if the Germans were give more than they ask for they would attack just the same, because they are possessed by the demon of destruction.

Ciano tried to mount a last-ditch effort to dissuade Germany from war, but this proved fruitless. Other moves to restrain Hitler both within Germany and without proved to be equally in vain. While was wrong in his belief that a Polish war wold not precipitate a wider European conflict, his behavior- what Ciano termed the "demon of destruction"- guaranteed that one would occur.

Sources

McDonough, Frank. The Origins of the Second World War: An International Perspective. London: Continuum, 2011.

Müller, Rolf Dieter. Enemy in the East: Hitler's Secret Plans to Invade the Soviet Union. London: I.B. Tauris, 2015.

Weinberg, Gerhard L. Germany, Hitler, and World War II: Essays in Modern German and World History. Cambridge: Cambridge University Press, 1995.