My most recent game (about a week ago), I went Communist Poland.
With historical focus off, I still went through my usual strategy the few times I've played Poland, setting up a fierce defensive line with a fortified circle around my main cities, and concentrating on building up large troops numbers, and then wait for the right moment to join the war for whatever faction, to tie up enemy troops (usually Germany & Romania).
I end up in the usual Danzig or War refusal, on my own vs Germany. They don't get through my defences.
At the same time Axis Italy, Germany, Japan & Spain start a war with the Comintern which also includes Belgium & France as Communist,
The Comintern get dragged into a war with the Allies (ie, the British & Commonwealth) because of a civil war in Iran.
The Axis & Allies also get into a war with each other, as Japan ends up taking out China and then the entire British Raj. It results in a ridiculous situation in Sibera, where democratic Russia (which has come up in Siberia as a result of a civil war) is being defended by Australian, American, Canadian & British troops, while next door Japan has their own troops in the region.
Eventually I join up with the Comintern.
The UK takes over Italy completely, while the USA & UK invade Europe and take Spain, France, Belgium, Italy and Germany until they stop at my Polish fort line & defensive wall around Romania.
All this mess paralyzes the Comintern AI and it becomes too stupid to do anything, and gets pushed back. The soviets go to closed economy (which ruins my ability to build tanks), and scraping the barrel (ruining their ability to produce anything).
On my own I have to I have to pump out huge numbers of troops & planes to:
* Halt the German advance on the Eastern Front.
* Halt the Japanese advance from India.
* Halt the Allied advance into Siberia
* Halt the Japanese advance into Siberia
* Take back Bulgaria.
* Take back Greece.
* Take Iran & Saudi Arabia.
* Take & hold Egypt.
* Hold the US advance after they take Germany.
* Defeat Democratic Finland
* Defeat Sweden
* Defeat Norway
* Take Turkey
* Take back Bulgaria
* Invade Germany, Italy & Spain
* Build a carrier fleet.
* Naval invade the UK, as well as clearing out the Baltics, the waters around the UK and the Med.
* Invade East Africa, and Naval Invade West Africa.
Now at this point, I've conquered Europe and have pushed through most of India. But I have so few troops and it's so hard to build enough weaponry that I'm stopped in Pakistan by Japan, no-one can move in Siberia either way. I've also taken half of Africa.
Eventually I island hop through the Atlantic and naval invade Florida, and eventually push through and capitulate USA & Canada. I've also given thousands upon thousands of weapons to France & the Soviets and they finally start producing huge numbers of troops.
I still then have to invade Brazil, so I can invade Uruguay which for some unknown reason is the last Allied major combatant despite just being default Uruguay. Allies defeated.
I now have 2 carrier fleets and surround Japan. Soviets actually naval invade and get on the Japanese mainland. I follow shortly after and finally take them out. I've declared war on Sinkiang so I can push through to China.
Finally the triple threat world war ends in 1957.
If you are the Soviets then really all you need to do is:
1) Ensure you survive the initial push from both Japan & Germany.
2) Ensure you don't leave open your southern flanks, ensure you can halt any attack from Iran, Afghanistan, Turkey, the Raj or China. In many games one or more of these countries will join the Allies.
3) Slowly push forward. Concentrating on conquering Europe first, then Japan to knock out the Axis first, then invade the UK. Look at the countries around you like Finland, Norway, Sweden, and consider invading them.
4) Don't neglect building at least 2 carrier fleets.
5) You have huge amounts of manpower. Your defensive armies can be so vast that the AI simply cannot attack them properly.