Just as in the real WWII there are some people that will change country for the sole purpose of relaying information to the enemy, changing the course of CV's to their detriment, etc. When caught in the act, there is little if anything a country can do. In real war, however, when these guys are found, they are shot. I propose a feature to "votekick" a player from a country for a period of time no less than a day. If a majority of fellow countrymen agree that a particular player is a spy, or by some other arrangement, the player is booted from that country.
It happened today and pretty much ruined the central battle. A knight changed country to Bishop, routed the CV toward the shore batteries, and ruined the attack, later he switched to Rook for the same sort of actions. Having a higher rank than the other Bishops, he commandeered the fleet and there was nothing that anyone could do about it. Had we the feature of a votekick, we could have at least saved the fleet. As it happened though, we ended up losing the fleet, did not gain the base we were attacking, and lost a port and another vehicle base besides. It pretty much ruins the game when such players are allowed to take such advantage even if players know outright what is going on.
Hope this helps, and no I'm not mentioning any names.
-Ghoule