Russian President Vladimir Putin is riding high amid Western efforts to improve ties in the aftermath of the Paris attacks. That has raised alarms in Kiev, where officials fear any rapprochement will come at their expense.

European Union officials say, however, that there is little appetite in key capitals, including Berlin, London and Paris, to win Russian help in Syria by abandoning Ukraine. One concrete sign is that the bloc is still heading toward extending economic sanctions imposed on Russia in the wake of the Ukraine...