Some Ukrainians fear that Putin’s real goal is a land corridor linking Russia and Crimea, the strategic Ukrainian peninsula Putin annexed in March after the Moscow-friendly government in Kiev fell.

A number of NATO officials have spoken of Putin’s “grand plan”: nothing less than resurrecting the Soviet Union, an ambition that — in Putin’s mind — would make a pro-Europe, pro-NATO Ukraine, looming on his very doorstep, a threat that must be removed or at least seriously weakened.

But other voices are not as shrill. Fyodor Lukyanov, the Editor of “Russia in Global Affairs” and the Chairman of Russia’s Council on Foreign and Defense Policy, believes that Putin actually lacks a big strategy, but excels at quick, reactive tactics. He told NBC News that the Russian incursion into Ukraine is all about pressuring Ukrainian President Petro Poroshenko to reach an agreement. “To let him know that the war is unwinnable,” Lukyanov said, “and to accept direct talks with the separatists.”