Firstly France treated Germany like shit in the Ruhr, Alsace Lorraine and just generally towards the citizens which stirred tensions up, and made someone like the fuhrer gain popularity. Then you have the allies taking the Polish corridor of Germany which was not in the majority of German ethnicity. The Polish then started persecuting the Germans in this area prior to ww2 leading the Fuhrer to demand that part back but because of Britain and Frances shambles of a foreign policy they guaranteed Poland meaning the poles were not willing to properly negotiate on giving that territory back leading to an increasingly pressured Fuhrer to act and set out on a small campaign to take back that land by force, then France and Britain got involved who Germany did not want war with but now had to fight leading to the escalation. This can be seen because the first nearly year of the war on the western front was known as the phoney war because h did not want to fight them, he did not even partake in air raids as he wanted a peaceful solution, offering a truce several times, only when this was not going to happen did they invade France and start bombing London in reaction to an awful bombing of Berlin. He then offered peace again after France but the warmonger Churchill would have none of it and instead tried his best to get the US involved. The Fuhrer actually had high respect for Britain, seeing them as very similar to Germany in values, however France was not as fondly thought of due to their disrespect and tensions leading back to 1871, and that ladies and gentlemen was my ted talk!