MOSCOW – One of the saddest ironies of this year’s commemoration of the 25th anniversary of the collapse of the Soviet Union is that Hungary and Poland, always the most restless of the Soviet empire’s captured nations, are now led by men mimicking Russian President Vladimir Putin’s governing style. They, too, are hollowing out independent democratic institutions and suppressing citizens’ fundamental freedoms. As the old saying goes, we become what we hate.

After the fall of communism, Poland an...