Putin has started a small invasion of Ukraine: he has recognized the independence of the two rebel areas (which he created with Russian money, arms and soldiers), and saying he will send soldiers there as "peacekeepers".

At one level, this announcement acknowledges a fact he has hitherto denied: Russian arms and troops are in Donetsk and Luhansk. At another level, calling them "peacekeepers" signals that they will attack. Putin's approach to truth is like Republicans': he reverses important truths to show that no one has the power to make him stop lying.

Because this is a small invasion as invasions go, it puts NATO in a quandary. To disregard it means Putin can seize anything and get away with it, as long as he does so by small steps. But because it is so small, any substantial response is too big, disproportionate.