I’m the Prime Minister of Estonia. Putin Can’t Think He’s Won This War.

To anyone who lived under Soviet occupation, reports from Ukraine replay scenes we thought we would never see again. The bombing of civilians and the wanton destruction of buildings recall the carnage unleashed on the European continent by Hitler and Stalin. In Mariupol, a port city subjected to a brutal, horrifying siege, residents are reportedly being deported to faraway places in Russia where an uncertain fate awaits them.

My family knows what that’s like. My mother was only a 6-month-old baby when, in 1949, the Soviets deported her, together with her mother and...