Surrender Feature in Games??

In real life and in history most countries tend to surrender after their capital and most of their main cities have fallen. Can you guys may be put this in the game as well, so that A.I countries totally surrender after most of their territory or main cities have been taken instead of fighting to the death over every single province.

Atleast make it so that their mainland surrenders to you but their colonies still stay on their side or something like France and Britain.