The guy who hacked your forums was the one who told you they were plotting against you. Clearly he had your best interests at heart when coming to you with this information and it wasn't an attempt at taking things out of context to get you to fight his battles for him against an alliance he left because he didn't get forum admin.
Also, you may have given them a clean state, but you never once contacted their leaders and neither did IRON. You claim that might makes right in this situation, yet it clearly doesn't.Instead of diplomacy you attacked them and then offered peace.