Attacking an ally

[Alter Ego]

I noticed that before I can attack an ally I must first use a diplomat to break the alliance, but i was wondering if the AI must do the same thing? as opposed to them just being able to attack me while the alliance is still on

[uanime5]

The AI also needs to send a diplomat to break their alliance before they can attack you. This is to stop your allies randomly declaring war on you.