Let's posit that somehow, with a fairly late & butterfly netting PoD, that France & Britain do not declare war on Germany over the conquest of Poland. Further, let us assume that Hitler meant to carry out the broad strategic steps for Germany roughly in sequence with what he wrote Mein Kampf. This means that although the "main event" of his program is the destruction and occupation of the Soviet Union, he simply assumes that France must be defeated and occupied as a preliminary step, because France, in his view, would inevitably act against Germany rather than permit a German conquest of European Russia. In OTL, even with the Allied DoW and Allied blockade, the German military was highly fearful that attacking the west would fail. They were unenthusiastic about the prospect. They succeeded in pushing back against Hitler's desire for an invasion in 1939, but went along with the northern and western assaults from April-May 1940 onward. This change of heart usually has not been explained. It implies that Hitler simply wore down military resistance to starting the war in the west through his own powers. Some have hinted that the Wehrmacht felt more comfortable with the western attack after the plan was revised to focus on the Ardennes & a year of preparations had taken place. However, how much can the Wehrmacht's change of heart be attributed to the fact that attacking the west sooner rather than later sort of made sense, given that the Western Allies had, you know, declared war, had imposed a blockade and were building up strength, even if they were not going on the offensive? There's pretty much universal agreement that delays of the western attack past summer 1940 would have been worse for Germany and better for the Allies than OTL, so that's a further endorsement of Hitler's eagerness to strike rather than prepare more, at least in summer 1940. But, supposing that somehow the west does not declare war over Poland, or impose a blockade, but just prudently rearms, and perhaps strengthens Anglo-French alliance ties. When Hitler, as is likely, advocates war against the west in 1940 or 1941, what is the dynamic between him and the military brass? In this scenario, despite western rearmament, the Wehrmacht can believe & argue that a war is patently avoidable and unnecessary. How easy or hard would it be for Hitler to overcome this opposition? A) No more difficult than the opposition he overcame in OTL 1940 -Fall Gelb begins on OTL schedule B) Impossible, he is removed from power for advocating a war with the west C) Pyrrhic-ally possible - He can crush military resistance to launching a war in the early 40s, but related purges and centralization damage military capability and enable metropolitan France to hold out D) Bending the military to his will takes several years, postponing the war for several years. More generally, how much of a difference did the Allied declaration of war over Poland make a difference in Germany later attacking the west. Was it a relatively large or small factor?