If one of the 'Big Three' (UK,USA & USSR) weren't involved, could the other 2 have defeated the Axis?

Question:

So, remove just one of the allies from the war.. could the other two have coped with the Axis threat? For instance, without UK it's unlikely there'd have been a Western Front or North African theatre.. would that have made it impossible for the USA to operate effectively against Germany? Or left the USSR exposed to the full force of the Axis? Without the USSR could the Western allies have ever launched D-Day? Without the USA would a 2nd front ever happen? Would UK have lost it's Empire to Japan? Would Japan have turned on Russia without it's need to fight both Western allies in the Pacific?
Note: Just to make things simpler, when I say UK, I'm including Empire & Commonwealth... no disrespect to those allies at all.. it just gets a bit complicated to break it down too much. As these nations forces were integrated with the UK's command structure, I use 'UK' as un 'umbrella' term to cover them all (ie. Australia, Canada, New Zealand, Sth Africa, etc).

Answer:

Probably not.

Had Britain surrendered in 1940 the Germans,undistracted by a 2 front war,would almost certainly have defeated USSR in 1941 or 1942, and then USA - even with the best will in the world - would have found an invasion of occupied Europe from 3000 miles away across the Atlantic impractical to say the least,and would have had to face 100% of the Germany ground army on landing rather than 20%.

80% of all German losses in WW2 were on the Eastern Front;the prospects of a successful UK/USA invasion of Occupied Europe facing the full might of the Wehrmacht on the ground if the Soviet Union had earlier been defeated or had not participated in WW2 would have been slim,particularly as German airpower would have been greater and thus the air supremacy enjoyed by the Allies over northwest Europe - a large factor in their success - would have been absent.

Without USA,the Soviet Union would not have received the 10 million tons of strategic raw materials sent by America under Lend-Lease,nor the thousands of tanks,aircraft (although admittedly mostly obsolete models) trucks and guns supplied in 1942 which kept them in the war that year.This could well have meant defeat for the Russians on the Eastern Front.Britain,without US forces,although in no real danger of a German invasion,would have been unable to launch a successful invasion of Occupied Europe,which would then have remained under German control much longer.

In the Pacific,The Japanese would not have had too many problems consolidating their hold on conquered areas if there had been no USA to fight,so their control over these areas would also have lasted much longer.

The Axis was sufficiently powerful that it took a combination of Imperial Britain,Communist USSR and capitalist USA to defeat them.Without any 1 of these 3 in the alliance,the Axis would have been able to achieve at least a negotiated peace on favourable terms,and possibly even outright victory.

As Stalin said about the alliance and its victory
Britain provided the time
Russia provided the blood
America provided the money

and all 3 were needed to defeat the Axis.