How dangerous is life in exile for a Russian critic of Vladimir Putin? Dangerous enough that Arkady Babchenko was willing to fake his own murder to help Ukrainian security officials foil an assassination attempt.

On Wednesday Ukrainian authorities announced that Mr. Babchenko was alive a day after they said he had been shot and killed as he opened his apartment door in Kiev. Ukrainian officials didn’t release details of what they said was a plot hatched in Russia to kill Mr. Babchenko, though they have made one arrest.

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