So this just happened.
Some background. As Manchukuo I was initially dragged into war against China by my Japanese overlords, shortly afterwards I declared war of independence through national focus and swiftly earned my freedom as they had hard time fighting both me and China. War against China was slow, as I needed time to build up my industry and armies to be able to take on increasingly wider fronts. Eventually I was able to overpower China and the final push began.
BOOM! Suddenly Xibei San Ma took over Chinese leadership, white peaced with Japan and dragged me out of the war with no gains (working as intended?). Crap! Now I have to start all over, I thought to myself. No matter, they're probably still extremely weak and I can probably just declare war again. But things were about to get worse. As I was relocating my exiled armies back home, Xibei San Ma suddenly decided to re-enter the war, leaving all my hundred divisions behind enemy lines out of supplies. At the moment I'm scrambling everyone to re-establish any supply lines I can.
Shortly after taking this picture Korea also joined the war, which normally wouldn't had been a problem, as I had 17 cavalry divisions garrisoned along the coastline, ready to delay the enemy in case something happened. However half of them are now trying to get supplies going again and I think I'm screwed.
Now, I don't have anything constructive to say, but this is clearly not the optimal way the game mechanics ought to work and should probably be looked at. I'm all for challenge, but currently I'm contemplating whether this game is fun enough to continue. Perhaps a break is in order.