LOL way to rewrite History, America did not intervene, Japan attacked you and Germany declared war on you.
And if you are really interested in the merits of all the fighting men I recommend Max Hastings Armageddon.
There are conflicting reports but most agree about 3/4 of German losses were on the Eastern Front fighting the Soviets.
The Germans and Soviets when well led made better soldiers, coming from dictatorships where life was cheaper, they were able to withstand the horror and death of war. many also were brought up in martial environments the Hitler Youth and Kommosol both had a strong death and glory cult
On the Western side many had to overcome religious and western liberal upbringing before they could pull the trigger.
"The Germans and Soviets when well led made better soldiers, coming from dictatorships where life was cheaper, they were able to withstand the horror and death of war."
Germans yes, Soviets no. Clearly there were some elite Soviet units and many, many brave Soviet soldiers. But the sheer number of Soviet prisoners (several million) precludes any claim for their man-for-man superiority.
The Finns certainly weren't overly impressed with the Soviets during the 1940 Winter War. The Soviets started fighting better at places like Stalingrad once it finally dawned on them that they were in a war of extermination.
Seppels question and my comment were reguarding WWI or the Great War as it was called at the time, in America we like to say, "Reading is Fundemental".
"The Germans and Soviets when well led made better soldiers, coming from dictatorships where life was cheaper, they were able to withstand the horror and death of war."
Perhaps.
And for the same reason Russians and Germans were always inferior seamen and inferior airmen when compared to Western forces.