By the fall of 1944, it was increasingly obvious that Germany faced invasion and defeat. That would come at the hands of the British and Americans and their allies coming from the west and by the Russians moving from the east. Only the most deluded of Nazis, including Hitler, refused to accept the realities of the military situation.
The D-Day landings in France in June 1944 had seen the Allies make steady progress across France, heading for Germany. A last toss of the dice by the Germans came with the Battle of the Bulge in December 1944, a massive German attack in Belgium and France. Despite initial successes, however, the assault was broken. At best, it delayed the arrival of foreign troops on German soil by a matter of weeks.
On the Eastern Front, the Russians had also started to roll back the Nazi forces with the June 1944 Operation Bagration. That action smashed the German Army Group Center. The victory was then rapidly followed by Nazi withdrawals from Poland and the Ukraine, then retreats from Albania, Greece and Yugoslavia.