Why Putin Is Watching Bulgaria's Election Closely

Bulgarian voters will go to the polls on Sunday for the fifth time in two years, hoping for an as-yet elusive result from the ongoing contest between Boyko Borissov of the center-right GERB party and Kiril Petkov, who leads the We Continue the Change and Democratic Bulgaria anti-corruption coalition (PP-DB). Both are former prime ministers.

Bulgaria, a NATO nation since 2004 and a European Union member since 2007, has—at least publicly, been lagging behind its alliance and union allies in supporting Ukraine in its year-long defense against Russia's full-scale invasion.

Hamstrung by months of...