So i'm playing as japan, and conquered China. Some damn rebels popped up in my newly conquered regions near mongolia, and i've quickly finished them, but not before they snatched two provinces in areas I cannot access. I move my armies there and all that I get is a stupid sound and a annoying red X saying that I can't go there and recover them. WHY!? The regions are hills and deserts. I've tried sending in only marines, mountaineers, cavalry - nothing works. Please help!