“They did not want a two front war”
No, who would? Unfortunately, you can’t conquer Europe without dealing with both the east and the west.
“They needed one for France and Russia.”
Why? Because one or the other might attack them, and eventually the other when their back was turned? Possibly, originally. ut that’s not how it turned out, considering Germany moved first. And even if it was the case that they planned offensive operations just in case at some point in the future it became The World Against Poor Germany, we generally don’t condone such practices. The Soviet Union had reason to believe it might be invaded again, but that did not justify them building an Evil Empire in Eastern Europe, Asia, and elsewhere in the meantime.
“When Russia invaded East Prussia, the war was on.”
Ugh. Please, please, please consult a timeline.
“we generally don’t condone such practices.”
Oh really. Which is why Russia is the good guy here?
Look, America so far is 2 for 2 for coming in late to European wars, leaving Britain and France out to dry, and fighting just in time to save their communist allies.
They did it in 1917, only coming in after the Revolution, and they did it again in 1941, in coming in at Pearl Harbour, after Barbarossa and the Russians were in.