This historic agreement between the two ideological juggernauts in europe all but assured minor mutual assistance between both rivals in a pivotal time of western failure. The Soviet Union & Third Reich exchange sectures of Poland, scaring the western democracies & assuring Hitler of valuable material, & Stalin eastern protectorates for the USSR.
The swift advance of German motorized Panzers division swift across French plains with ease, quite literally shocking allied movements & supply lines with swift air raids. The staunch contrast of this new German doctrine when compared to Ww1 proved decision to destroying the French state & english moral at Dunkirk in only meer weeks. With swift surrender in Paris, the new vichy puppet government further emphasised the english hopelessness of this now unstoppable German onslaught.
The Luftwaffe's bombing Blitz of English industrial points and aviation bases ravaged the general populace of Britain. This hefty attend to subdue to RAF though ends in failure as Hitler sets site on civilian targets in attempt to break moral along the countryside. Thus allowing the RAF to reorganize the counter the German Blitz by 1941, ending German momentum in the west and giving the English time to fight another day.
An ambitous military campaign organized by German elite ends in disaster as the German army is to extinguish the Soviet ambitous to ruin Hitler's planned Reich. While successful intitally, German general find themselves unable to supply the Blitzkreig for as quickly as their panzers toil of harsh muddy Russain winters. The Battle of Stalingrad becomes the nail in the coffin for hitler's ambitous dreams for living space as the German 6th army is encircled and destroyed. Thus paving the way for an onslaught of Soviet counter attacks.
Advised by the elite imperial Japaneese command, Japaneese emperor approved the planned surprise attack of the US port of Pearl Harbor in Hawaii. This attack provoked the sleeping giant that is the United States, & failing to decisively down to US Pacific fleet. This pitted the 50 states againest the Axis powers in full force & industrial might alongside the Allies. In time this simgular act prooved admittly the biggest mistake for the Axis as the industrail might for the United States overwhelmed and crushed the dryed Japaneese & German Reichs as they failed to support their own army branchs.
The D-Day landing invasion along the coastline of French Normandy all but assured the emdomg of what was planned as a "1000 Year Reich" for Nazi Germany. US, English, Kiwi, Aussie, and Canadian efforts pincered the beach heads and German defences to assist in the race for Berlin in 1944. Without such a successfully planned invasion, today's Europe would've seen a much more red political apperance indeed.