What I got so far:
-There are 4 players. Players 1 thru 4 are allied to player 5.

What I want to happen:
If one of the 4 players kills one of player 5's units, a "City Alert" goes off causing players 1-4 to be able to attack player 5. And player 5 can attack players 1-4. They really when the countdown timer reaches exactly 0.

Here is problem:
-When I have made the triggers for players 1 thru 4 to become unallied to player 5, some of the players dont get unallied. The countdown timer triggs however do work.

I may have found a way to do this on my own. Im sorry, but I have tried alot of thigs and I thought i would never find it. Ill get back to u on it.

For the alliance activating triggers for players 1 - 4, does your alliance action set the "current player" as player 5's enemy? If so, change that action to set "Force 1" (the force including players 1 - 4) as an enemy to player 5.