The Estonian government wants to ban the memory of the Soviet past from public life. Riots and Russian cyber attacks cannot be ruled out. At the center of the controversy is an old tank. Lenin got it: his statue still stands in Estonia’s third-largest city, Narva, but it was moved to a secluded, walled-in corner in the courtyard in the 1990s. In the summer, the Russian revolutionary leader was surrounded by an ugly construction site fence. If the Estonian government under Prime Minister Kaja Kallas has its way, all Soviet monuments in the small Baltic state should disappear from public...