 NATO clearly throughout the Cold War helped deter Soviet aggression in Europe, but now faces a large scale war in Europe with Mr. Putin's full scale invasion of Ukraine, which has unfolded over some years. And to try and match that, NATO has been spending much more on defense, particularly in Europe since 2014, where spending has gone up by about a third to strengthen its defenses. But it's still got a long way to go. NATO has a formidable fighting force, but the war in Ukraine has shown us what protracted war looks like.