Part of the response from the WH today:

“Second, the former Vice President makes the clearly untrue claim that the President – who is this nation’s Commander-in-Chief – needs to realize we are at War. I don’t think anyone realizes this very hard reality more than President Obama. In his inaugural, the President said “our nation is at war against a far-reaching network of violence and hatred” […]

There are numerous other such public statements that explicitly state we are at war. The difference is this: President Obama doesn’t need to beat his chest to prove it, and – unlike the last Administration – we are not at war with a tactic (“terrorism”), we at war with something that is tangible: al Qaeda and its violent extremist allies. And we will prosecute that war as long as the American people are endangered. “