Vladimir Putin and Barack Obama had a contentious phone call today, after Putin got retroactive approval for his military invasion of Crimea — and perhaps beyond. That seems to be the point of Putin’s readout of the phone call, anyway (emphasis mine):

Vladimir Putin had a telephone conversation with President of the United States Barack Obama on the American side’s initiative.

The two presidents discussed in detail various aspects of the extraordinary situation in Ukraine.

In reply to Mr Obama’s concern over the possibility of the use of Russian armed forces on the territory of Ukraine, Vladimir Putin drew his attention to the provocative and criminal actions on the part of ultranationalists who are in fact being supported by the current authorities in Kiev.

The Russian President spoke of a real threat to the lives and health of Russian citizens and the many compatriots who are currently on Ukrainian territory. Vladimir Putin stressed that in case of any further spread of violence to Eastern Ukraine and Crimea, Russia retains the right to protect its interests and the Russian-speaking population of those areas.

That was the pretext that was entirely predictable from the start of this crisis. And it’s the pretext that will have tanks rolling across that border soon, unless we start providing more disincentives than we’ve done so far. One might be the immediate restoral of the missile-shield program and some ground-breaking events in Poland and the Czech Republic, but don’t expect either nation to trust us to stick to it a second time.