If in their alliance page that is for everyone to see, They could put who they are at war with. remember the saying the enemy of my enemy is my friend.It would help newer players and the alliance that that the attacker is against.
they could but the downside of revealing their hands is larger. you don't go to Vegas, sit at a poker table, and announce "I'm new so can we play with our cards face up?". LOL I would be shocked if anyone was loose enough to reveal who their pacts and enemies are.