Could America have won WW2 without Britain?

In either theatre or both, although in Europe let's presume that UK (up to Hadrian's wall) and Ireland were in German hands.

Very difficult to impossible to sustain an amphibious assault without a logistics base nearby.

Realistically, the Americans would've had a negotiated peace.

out of intersts, why did you ignore the Canadians, Australians, Indians etc?

I suppose I was including them under the umbrella of the British Empire and Commonwealth as it then was.

Allegedly "British" troops kept suffering defeats to German forces of smaller numbers etc. in the early years of the war, not to mention in the Far East. Depending on which historian one reads, one can sometimes be left with the impression that Britain's role was actually not that significant.

I think that the Americans would still have nuked Japan and won the Pacific war but then negotiated peace with Germany.

Don't forget that Hitler had already attacked the US directly, by sinking US ships in the Atlantic and harassing the Eastern seaboard. I don't think it would have been at all easy to simply live and let live, politically the US authorities would have wanted to continue. It was also very much in US strategic interests to destroy the Nazi empire. I think the US would have gone on to nuke Hitler at the end of a longer and bloodier war with much greater US losses. Probably the Soviets would have reached Paris though by then.

Don't forget that Hitler had already attacked the US directly, by sinking US ships in the Atlantic and harassing the Eastern seaboard. I don't think it would have been at all easy to simply live and let live, politically the US authorities would have wanted to continue. It was also very much in US strategic interests to destroy the Nazi empire. I think the US would have gone on to nuke Hitler at the end of a longer and bloodier war with much greater US losses. Probably the Soviets would have reached Paris though by then.

But that was because America was supplying Britain with supplies and munitions.
If Britain had done a deal in 1940 or had been invaded that would not have been an issue. Hitler may still have declared war on America though in support of his Japanese ally. His ego would have been much bigger too.

Have you read BoJo's book on Churchill?

Don't forget that Hitler had already attacked the US directly, by sinking US ships in the Atlantic and harassing the Eastern seaboard. I don't think it would have been at all easy to simply live and let live, politically the US authorities would have wanted to continue. It was also very much in US strategic interests to destroy the Nazi empire. I think the US would have gone on to nuke Hitler at the end of a longer and bloodier war with much greater US losses. Probably the Soviets would have reached Paris though by then.

Unlikely. The Americans lacked the aircraft to carry a nuclear Bomb across the Atlantic and would've been delayed in their nuclear programme due to lack of British support.

I know that the soviets did a phenomenal job on ww2, but I'm yet to be convinced that they could've edge you defeated nazi her many by themselves.

Don't forget that Hitler had already attacked the US directly, by sinking US ships in the Atlantic and harassing the Eastern seaboard. I don't think it would have been at all easy to simply live and let live, politically the US authorities would have wanted to continue. It was also very much in US strategic interests to destroy the Nazi empire. I think the US would have gone on to nuke Hitler at the end of a longer and bloodier war with much greater US losses. Probably the Soviets would have reached Paris though by then.

It depends how long they had to develop things. In our alternative history, it could have been 1948 or 8 before they nuked Germany - and by then, they did have the long range bombers.

I think the truth is that the Soviets had a huge amount of US assistance, particularly in food, trucks and vital supplies, but without that, they could have eventually defeated the Nazis single-handed, but only with immensely more suffering and loss and more protracted battles. Maybe crossing the Oder in 1947 or something like that.

It depends how long they had to develop things. In our alternative history, it could have been 1948 or 8 before they nuked Germany - and by then, they did have the long range bombers.

I think the truth is that the Soviets had a huge amount of US assistance, particularly in food, trucks and vital supplies, but without that, they could have eventually defeated the Nazis single-handed, but only with immensely more suffering and loss and more protracted battles. Maybe crossing the Oder in 1947 or something like that.

I think that the Americans would still have nuked Japan and won the Pacific war but then negotiated peace with Germany.

I agree that's the most likely outcome. A German victory in Europe wouldn't affect the war in the Pacific much, because Germany and Japan never really cooperated in anything. And it's unlikely Germany would have launched any major attack on mainland North America for the same reason that America would then be unlikely to launch any attack on Europe - the material and logistic challenges of moving enough troops and supplies across the ocean to begin an invasion would be immense.

I guess it depends at what precise point our alternative history starts. If Japan had never attacked the US, the US would probably not have declared war on Germany in the absence of a reverse declaration for a long time. However, the German raids on US shipping started before Pearl Harbor, so there were already growing reasons for the US to be non-neutral as regards Britain, not to mention all the cultural and business ties. It's hard to come up with a history where the US does not get involved against the Nazis, in my opinion, although Robert Harris's nuclear stalemate between the Europe-ruling Nazis and the Western Hemisphere-bound US in 'Fatherland' is the most plausible one I've read. I haven't read Boris's scribblings, I don't like to send him money.