Speed Reads

Crisis in Ukraine

Ukraine pushes pro-Moscow rebels to final showdown in the last separatist stronghold

Even a few weeks ago, Ukraine seemed to be inexorably losing control of the eastern part of its territory to pro-Russia militants who were seizing cities big and small. By Sunday, Ukraine had ousted the rebels from Slovyansk and other towns, recaptured a key border crossing into Russia, and was preparing to battle for control of Donetsk, a regional capital of a million people and the center of the pro-Moscow forces' self-proclaimed republic.

The rebels, who call their convergence on Donetsk a tactical retreat, also seem to be treating this as a final showdown. The string of victories by Ukraine's troops started early last week, when President Petro Poroshenko called off a cease-fire.

The roots of Ukraine's improbable turnaround lie deeper, however: a shakeup in the military chain of command, an influx of financial aid from the U.S. and Ukrainian citizens, some military disengagement from Moscow, and what The New York Times' David M. Herszenhorn describes as "a crucial psychological shift: Soldiers surmounted a reluctance to open fire on their own countrymen, a serious issue after riot police officers killed about 100 protesters last winter during civil unrest centered on Maidan, the main square in Kiev."

Ukraine's ragtag military, plus allied militias, also adapted to urban warfare and benefited from what amounts to on-the-job training. "The military themselves learned to fight," Mykola Sungurovskyi, military scholar at Kiev think-tank Razumkov Center, tells The New York Times. The siege of Donetsk will be a big test of how far they've come.