I don't think they meant without US/UK aid - but I do think that by D-Day the Soviets had the game in the bag. Aided by SBRs from the western allies yes - but the land invasion of France did nothing but distract an already mortally wounded Germany. If the western allies had continued their aerial attacks - but not invaded Russia would still have won.
In fact - if in 1944 the US and UK had made peace with Germany - I think Russia would still have won. Germany had lost too much by then to be replaced. Not in terms of equipment - which German factories produced in large amounts but in terms of the loss of people; both Army groups south and centre - over 2/3 of their fighting forces - and the remaining third - battered and broken and trying to plug holes which were spread over 100's of miles of front.
I mean, don't get me wrong - I'm a brit. But to say that the Russians NEEDED us to invade France in 1944 is wishful thinking. They were begging us to in 1942 - and we didn't. Then arguably it may have made a difference.
Please note: I am NOT saying the Russians won WWII in europe without the western allies. Just that by 1944 they could have.
The UK/US liberated France - because by 1944 they were already preparing for the Cold War. To pretend it was out of 'honour' or 'commitment' is fanciful.
I know what you are saying Twigley, but to give the Soviets not DDay, but still the SBR campaign by the US/UK is huge. Those two powers rained down destruction day and night, quite literally on Germany, forcing the Nazis to fight two sides. If it was just the Soviet Bombers that would be different.
Had the Battle of Britain gone better for Hitler, he would have had more to throw at the Soviets to keep him on his timetable for attacking the US in 1945 and those US/UK bombings would not have thrown off his cross-Atlantic ship and aircraft production.
The landings in the North Atlantic and Italy were the Western Allies response to the Soviet's asking for an invasion in '42 and while they were not landings into European mainland, they were direct attacks against the Axis that had to be countered by the Nazis in particular, pulling away troops and materials from the Eastern Front all the while while the SBR campaign continued to rage.
It really becomes a lot of conjecture...