Obama very specifically said that this was 'not an act of war': http://www.theguardian.com/us-news/video/2014/dec/21/obama-n...

He has to say this, otherwise the NSA has started an act of war against pretty every country on earth, so it would be pretty hypocritical.

Obama knows this, so he can't go and classify the US as starting wars through their own cyber 'crimes'.