Usually, if you make a mistake and lose your captial early in the game, don’t you generally have enough forces close by to take it back? I can see where this could happen with Japan, UK and Australia, but with Germany, Russia, US and even Italy, there should be sufficient forces close enough to take the capital back.
Also, doesn’t something like this usually happen with a small attacking force? I mean, you would pretty much notice a large buildup within range of your capital, right? eg. Japan leaves Japan totally undefended not noticing an American transport with men on the Marianas. Result: US moves transport to SZ 6 and takes Japan. In this case, I could see the possibility that all Japanese transports are out of range of Japan and thus Japan is pretty much taken out of the war.
Another example: Moscow is left undefended as Russian forces are moved up to block German tanks. Meanwhile, a Japanese tank manages to sneak up to Kazakhstan and Samara is unoccupied. Result: Japan takes Moscow with a single tank. In this case, don’t you think there would be enough Russian forces to come back and retake Moscow? Granted, the loss of cash to Japan and losing the Major IC would be a large setback to Russia, plus all the forces pulled back to retake Moscow would enable the Germans to push forward faster so it will probably be game over for Russia in another couple of rounds. Or maybe not if the German advance isn’t fast enough and there are no other Axis forces to keep up the pressure. I’m just saying that losing one’s capital doesn’t always mean game over.
This is something I like about the captured Major IC rule. Since it drops to a Minor IC upon capture and the invading force can not upgrade to a Major, it at least gives the owner of that capital a chance at retaking their capital by not allowing the invader to suddenly plop 10 guys there for defense. Assuming the battle for your capital was tough, there probably isn’t a heavy surviving invasion force so with them and maybe 3 new guys, at least you have a chance. With 10 new guys, forget it. Unless you just happen to have a stack of 20 tanks (plus 20 transports for Japan & UK) that were sitting around outside the capital.