personally, if I am allied with someone and they start building up forces near my locations, I'm gonna start preparing for the worse, and I'm not going to need the extra turns like that.
I personally just think its more fair that if I declare war with someone I'm peaceful with that I can not attak them that turn, but they should not be allowed to attack me, either. Whoever declares war should be allowed to be the first aggressor.
I guess things are different on a small map (like I'm playing, war of the 12 mages), because 1 turn is more then enough time to get alot of defenses ready.... 2 turns actually, because I had to break the alliance the turn before.
Paladino and I came to a fair compromise in our game about how to handle this, but it was a complicated process because we were allies, and allied victory is off. there was also 1 computer player left, who has been turtled all game (and who i was at peace with) to add to confusion.
without a computer player left, there is no argueing that the alliance had to be desolved and we had to declare war so we could have a victor. War should have been set up near immediatly, with 1 player breaking the alliance, the next declaring war (and either attacking freely next turn or having both players needing to wait 1 extra turn to regroup). However I felt the turtled cpu should have been considered 'eliminated' for all intensive purposes (we were not playing all cpu had to be killed before humans did), and paladino did not.
I can see needing the extra turn on a larger map (but the 'defender' should not be allowed to attack first anyway!), but I think I'll be setting up specific rules for that map from now on... which would have been the smart thing to do to begin with!