At the same time, if he’s at all rational (and this is the worrying thing—it’s not clear that he is), Putin would calculate that escalation is not a winning strategy for him. He could invade the eastern slices of Ukraine, especially around Donetsk, but he couldn’t go much further. The move would rile the rest of Ukraine to take shelter under the EU’s (and maybe NATO’s) wing, and it would rouse the Western nations to rearm to an extent unseen in 20 years (and to a level that the Russian economy could not match).

This would not be a revival of the Cold War. The Cold War was a global contest, in which the capitalist West and the communist East vied not only in the occasional proxy war but also for ideological allies. No countries, besides a handful not worth having as allies, support Russia in this standoff, and many of the neutrals would join the opposition if Russian troops crossed into mainland Ukraine.

So Putin probably doesn’t want to invade, if he has other ways of accomplishing his goals—and Turchynov’s acceptance of a federalist Ukraine might be a big step toward that goal. Yes, it would probably mean the end—or at least a very long postponement—of many Ukrainians’ hopes for a place in the EU’s sun. For Putin would use his foothold in eastern Ukraine—the country’s industrial heartland—as a lever to keep the other half of the country from drifting out of Moscow’s orbit.