Back in the USSR
Well, in March of 42 I had well over a hundred divisions lined up on the Soviet border, along with a number of allied troops from my puppet regimes. I declared war, poured my ridiculous IC into reducing the 10% dissent, and poured over the frontier.
It took me about three months to slog to Leningrad, Moscow, and the Crimea. It was an unimaginative, brute-force operation. Very few encirclements- I just kept nudging the Soviets east. Without the Nazis around to trigger a Great Patriotic War, the Soviets had lousy ground defense efficiency.
In July, the Brits landed at Arkangelsk. While my line faced increasingly stiff opposition, the Brits were able to waltz into the Urals and start marching south. They also seized Vladivostok while I was trying to set up a viable defensive line in Manchuria.
(This is what I was setting up with the British/German collaboration: tricking the Americans into taking the brunt of the fighting while the Brits/French took enough territory to prevent the setup of an American puppet Russia. Then, an exhausted America would have to give up its hegemony in Europe to keep the Soviet prize- or vice versa.)
The British incursion broke the Soviets as they moved troops to face the fifty or so Allied divisions pouring through their back door. It took me about a year and a half to take the last Soviet VP at Okhotsk. Britain seized about 2/3 of Siberia and the Urals.
After Soviet resistance slackened, I moved divisions back to Europe. In late 1943, I puppeted Nationalist Spain, Italy, and couped Portugal.
So: October, 1943. The USA stands triumphant over the entire world. I've liberated all of the USSR's European SSRs and defeated every non-democratic regime in Europe. I have vast military superiority over every other nation. I'm building a level 4 nuclear reactor and my first strategic rockets. My troops are positioned to take out Tuva and Mongolia, and then begin a blitzkrieg war on the Fascist Republic of China.
And then? Game crash. Ouch.