Was the Cold War necessary? Was it Moral? if so or if not, why?!?

I'm doing a project in my History cl and I'm gathering up opinions from different people inorder to make my final decision. It would be nice if along with your opinion, give me reasons why you feel that way about the Cold War and examples from your research or whatnot. Oh! Please attach the site or the Title and Author of the book/encyclopedia you used so that I can reference it and look it up.