Actually this is not something very new if you have read all the previously recommended links in the article that started this serie "Artificial Inteligence". This new article is proving that depending on environment (how abundant resources are, goal definition and the connections between AI agents) the behavior of AI can be either aggressive or highly cooperative.
The full story can be found in the article Google's New AI Has Learned to Become "Highly Aggressive" in Stressful Situations. Following quotes are from it:
(...) the message is clear - put different AI systems in charge of competing interests in real-life situations, and it could be an all-out war if their objectives are not balanced against the overall goal of benefitting us humans above all else.
(...) the initial results show that, just because we build them, it doesn't mean robots and AI systems will automatically have our interests at heart.