What are people's opinions on Alternate History Hub's "axis victory" scenario? Quite honestly, it's one of the more realistic ones I have seen, one that doesn't rely on Germany winning every battle.
View: https://www.youtube.com/watch?v=FME3eEcvhss
TL;DW
Dunkirk fails, utterly. There is no rescue, no miracle. BEF is just completely defeated due to weather not allowing evacuation and taken as POW. This craters British morale, as there are now hundreds of thousands of POWs that pro-peace faction will use as rallying cry, to demand "bring our boys home". Fundamentally, Germany does not win through force of arms, but through British will to fight not being there, and a peace talks are started little while later. End result is a Germany that doesn't need to concern itself with Western Front, nor one that loses most of its experienced pilots in Battle of Britain.
As such, Barbarossa ends up being more lopsided as Germany now has still fully functional Luftwaffe to support their operations, as well as being able to deploy almost all of its forces to East, rather than needing to split between various fronts. Extra ammo, extra manpower, and functioning Luftwaffe might not mean complete defeat of USSR, but either Stalingrad or Moscow is going to end up falling, and there won't be Lend-Lease this time to stabilise Soviet front and keep them in the fight. Why?
Well, US is happy to sit this one out. Without Britain in the fight, US administration has no real reason to get involved. They might not
like Germany winning, but they won't get involved without Britain serving as their connection to Europe.
End result is that, effectively, Germany has won. They will proceed to take a break and start working on challening Britain on the seas with new Kriegsmarine. Japan attacks Pearl Harbour and drags US to the Pacific War. Axis powers effecticely dominate at this point. D-Day without Soviets draining Wermacht is not really possible.
Of course, he does end with the note that US is still going to finish Manhattan project, and in this time line, once new conflict starts with Germany joining Japanese and challenging British on the sea, the original plan to bomb German cities with nukes is propably going to go ahead. And those nukes will be game changers.
TL;DR
Dunkirk is disaster and British will to fight collapses. Germany doesn't suffer losses in Battle of Britain, and is able to throw its entire might at Soviets, who don't get Lend-Lease as Lend-Lease program is never started to support Britain. Germany will be able to achieve at least one of it's goals, which makes achieving other two goals easier. End result is pacified Soviet Union. Next conflict will end up with US dropping nukes on Germany, as those are only way to break their hold over continental Europe.