oh.. well... crap.... I'm not going to keep playing the game until turn 250 just so I can win on time. I misunderstood what you meant when you said only the Russians could win domination, I thought you meant because they started so big and had less land to take over. I guess it was just purely by chance that I never tried to declare war on an "Ally" country... so I only found out about this now.
If you wanted to keep it this way... then why is Russia not one of the allies? China and Arabia are permanently on the Allies side, but Russia isn't? That doesn't make much sense at all.
I would do one or some of the following if this was my scenario:
1. to make it a better "WW2" scenario, set the starting point to 1942 instead of 1939 like I suggested before. That means Russia is at war with Germany and Italy (but not yet with Japan- that happened in 1945); the USA is at war with Germany, Italy, and Japan; the Germans have already taken over France and Poland (maybe Vichy France could be made a city state and Warsaw could be a city under German occupation); and Japan already has a foothold on the Asian mainland and destroyed much of the American naval presence in the Pacific (apart from their aircraft carriers).
If you do this... you could take away the permanent peace thing... the world is already at war as it should be at the start of the game and then WW2 has 7-10 turns to play out.. after that things will happen as they do.
2. If that's too much work, then just make it a "1939" scenario and not a "WW2" scenario. Take away all the Axis and Allies permanent peace nonsense.. and anybody can play this scenario as an alternate reality starting in 1939. Similar to the classic Civ IV "1000 AD" scenario... I loved playing that scenario.. but I was never trying to go for historical accuracy. For example I found one of the best ways to win as the Arabs was to convert to Christianity and make peace with the Europeans as soon as possible.
3. If you don't want to let go of the small claim to historical accuracy this scenario has... okay... leave it as is (maybe reduce the turn limit to 100 turns instead of 150)... but AT LEAST make the Russians one of the Allies. That was the one huge event that happened early on in my game that sent me on a very different historical path... when Russia declared war on me (China). But personally I think option 1 or 2 is a better overall choice for maximum replayability.
It makes me sad
I can't finish the scenario. I was still having quite a bit of fun... but the only thing I had left to look forward to was taking out the British and the Americans. but I can't do that, even though I played long past when the events of WW2 were relevant.
Have you tried using the live tuner? IIRC you can force declare war using it, though I could be wrong about that. It's worth a check if you're really wanting to go to town on the remaining challenges in your current game. If you've never used the tuner just google it "firetuner Runtime Lua Console", and read up on how to activate it for use. After you've got it up and running it's pretty user friendly to figure out.
As far as the Soviet Union not being part of the Allies in this scenario, I did this based on my current knowledge of World War 2 history & also some considerations for the scenario. I'm certainly no historian, but I've always had an interest in the war and have taken a course focused on it as well.
Hitler & Stalin initially had a non-aggression agreement at the invasion of Poland (that Hitler would eventually go against), so that they could divide it up. I had previously made it so that Russia starts out at war with Warsaw, but the world builder messed this up somehow so I ended up just scrapping it.
The west generally didn't trust the USSR and Stalin was supremely paranoid to the point that he probably distrusted the west even more than they did him. Many westerners actually considered Hitler to be a bulwark against the spread of Sovietism prior to Hitler going off the deep end with his aggression in Europe.
Most historians agree that Hitler declaring war on the Soviet Union (along with the United States) was one of his biggest blunders of the war. Since there is no way to script events like this I thought it would be nice to allow German civ players the option to try to play defensively against Russia, and focus more on taking Great Britain & the middle East before any potential Barbarossa campaign. Regardless, a war between even AI controlled USSR & Germany almost always seems to occur due simply to their proximity after Warsaw is captured.
China and the USSR are not equivalent in their relation to the Allies in WW2. The USSR was far more powerful, and did not rely on any western power for aid and defense against Japan. In fact the Soviet Union successfully beat back an offensive from the Japanese by itself in the Mongolian conflict leading up to the war in the late 1930s. China on the other hand, was heavily reliant on foreign policy from the west to prevent Japan from exploiting it.
Also, Stalin and FDR are certainly not equivalent in their relation to their joining the Allies in WW2, so I think the distinction between their civs in the scenario is ok.
On Arabia, I'm not very clear. I thought it was under heavy influence from GB leading up to the war and had little to no axis leanings, so it seemed to make sense that they were a standard ally.
The consideration for the scenario is to sort of keep Germany from getting squashed too early in the game. If the USSR is an ally like the US, then it will almost undoubtedly declare war on Germany around turn 10 or so when it had lost a lot of units from fighting in Europe. With the ability to war with anyone it wants, it tends to do stuff like invade Iran or Turkey instead. Neither of which is historically correct, but it makes the game more interesting in my opinion then the Nazis getting wiped out 15 or so turns into the game.
The other reason for the game's current setup and probably the reason for your game going on a strange tangent are explained in the opening post. The AI views civs that are conquering other civs as aggressive or "warmongering" regardless of who is an Ally or part of the Axis. That's why I made Manchuria owned by China in the early game, and also why I have seemingly pointless events like Warsaw/Seoul starting the game as free city-states. Otherwise the game would see China as the aggressive warmonger if it began to take back a Manchuria that Japan started off controlling.
As is, civs like Japan & Germany (possibly Italy too) are consistently seen as warmongering aggressors by the other AI controlled civs. This is a good thing.