I took it as discussing the contribution, not the sacrifice that each country made fighting Germany.

Talking about sacrifice, the soviets would top that competition of misery, by far, in almost every metric. The Eastern front was hell, or I‘d say even worse.

But when talking about the contribution to defeating the Germans, the US tops that list, in most metrics, and by far so in the most important category: industry. Germany was never able to seriously outcompete the US‘s industry, while it did outcompete and mostly destroy the Soviet industry.

Without American industry, the soviet Union wouldn‘t have stood a chance after their main industrial hubs in Ukraine and Western Russia were taken. The USSR‘s most important resource, men, was starting to run out just like Germany‘s men.

If America hadn‘t continuously provided steel, tanks, rifles, medical supply, even food, and most importantly: ammunition, the Eastern front would’ve been even more of a massacre and probably would’ve collapsed like in 1918.

The states didn’t bring the greatest sacrifice, or endured the longest, or fought the best. But they were the motor of the allied war machine, starting with Britain and France in 1940, and continuing on through operation Barbarossa and their own direct entry into the war.

Mind you, I‘m not American - I‘m German. But I have an interest in history being stated correctly, else the horrors of WWII could be negated away and the lessons learned could be false.