When does the AI "quit"

[hveldenz]

When do forces on the AI actually quit? I have had games in my US-China 90s campaign where I obviously have "won" with all objectives and seemingly all the enemy killed or off the field. The game sometimes goes for 2,3 up to 5 more turns before I 'win' for sure. It seems to be on advances, assaults, and to a lesser degree the meeting engagements. The AI throws in quicker on Delays it seems. When I look at the Player 2 forces at the games end, I literally have killed every single unit except for a rare pinned/routed inf unit. Would not Morale break and a force withdraw when all objectives are lost at something less than 95-99% casulties?