His methods taken were unappreciated and uncouth. Therefore, he is no protector of mind. The Fascists were helping in the war against communism, and even regularly attempted near their downfall to surrender all chain of command over to Allied forces in the fight against Soviet Russia. The US viewed Stalin as a geopolitical enemy, but not one that warranted allying with former enemies/undesirables.
Illidan is a traitor to his kind, what do I care that he wanted in some sense the same ideal as myself? He does not follow my aims and he is a loose cannon. Therefore he is my enemy.