On June 22, 1941, Nazi Germany broke its non-aggression pact with the Soviet Union, invading the Russian-held area of Poland. Nazi tanks streamed across the border between the two occupiers, arriving in the Lithuanian town of Raseiniai the next day. The resistance there almost threw a wrench in the entire Nazi war plan. As the Nazis advanced on the town, Soviet mechanized divisions moved to defend it. The local tank garrisons happened to be equipped with Kliment-Voroshilov tanks, an advanced armored vehicle invulnerable to almost anything the German infantry could throw at them. Anti-tank weapons were useless. The Nazis tried...