You are completely missing my point. By butterfly effect I meant bigger changes, much bigger. The two biggest things Hitler could have done to help himself are: not declare ware on the USA, not declare war on the USSR. Those two countries (mostly the USSR to be honest) did most of the work in the European theater. By the time operation Barbarossa got screwed up only England really stood against them in any meaningful way. Sure, the US might have tried to enter the war later, but at that point they would have already lost most potential footholds.
The third big thing they could have done: don't hold back against England just because they were racially similar to Germans. There were numerous things, such as anthrax attacks and bombings, assassinations and invasions, as well as failing to overtake the retreating British forces at Dunkirk that could have utterly crippled the British forces and allowed for the UK to be taken relatively early. However, Hitler didn't want to be too harsh on them because of their common ancestry.
This is looking at only one side of the equation.
First, the British had chemical weapons as well. If the Germans started using chemical or biological weapons in their attacks on England, the British were
entirely capable of retaliating in kind. And again, the British were outbuilding the Germans when it came to new-construction aircraft, and that's
before you get into what the Americans started selling them as the war continued
I cannot overstate how important the MAD factor of chemical warfare was. Every part of Germany was within range of British bombardment, but this was not the case for Great Britain. Britain would doubtless be devastated, but Germany would have been gutted, and the nazi party likely overthrown for opening that box.
Second, not declaring war on Russia still doesn't build Germany a Navy capable of contesting the Royal Navy. Aircraft carriers are a moot point fighting in Europe and across the English channel, but the Kriegsmarine was inferior to the RN in
every regard except for U-boats, and those U-boats were never enough to do more than harass. It takes
years to build Battleships, at least a year or two to build a Heavy Cruiser or Light Cruiser, and nothing else was going to be able to contest the
massive British naval superiority.
With the Luftwaffe incapable of defeating the RAF,
even if Russia had not entered the war, Germany lacked the capability to knock the British out of the fight. And this is
before you get into the issue that the nazi party's socialist policies were steadily eroding the institutional competence of German heavy industry.
And this isn't getting into how the ideology of the Nazis and the Soviets
both ensured that they would eventually go to war with each other.
A more plausible alternate history is Germany launching Barbarossa a couple months earlier, and actually succeeding in taking Moscow. Russia still wouldn't quit, but their ability to contribute would be drastically reduced. Maybe in such an AU Germany would make peace with Britain in exchange for withdrawing from France, which would then be demilitarized, but that's unlikely. The British drew the line at the invasion of Poland, not France, and Churchill was very unlikely to back down on that.
