There is no reason to declare war on MIA now. Currently we can't do nothing to help them. I would recommend KISS to abandon near all home continent cities. Transport some units to our continent, pillage everything they can, disband all workers. They can block their coast so MIA won't able to land units. Naturally MIA can't send units trough our lands. With KISS's new core on our continent they can do some research and help us win this. They would be Vassal State for us. On tech front After Nationalism comes in. Research Steam Power do it fast. So we can smoothly swift units as were needed.