Look I don't care about your attack on me, I don't care about the infra, tech and land you destroyed, there is no need to go down this destructive route. Make some friends have some fun, hate isn't a good thing to hold onto even in a game
An alliance is more like someones house, so if you went to someones house and sat down on the couch without asking for permission they are perfectly within their rights to ask you to leave.... and in this case you came into the house and hit someone...