On December 31, 1941, after more than half the Jews of the Vilna Ghetto had been executed by the Germans in the nearby Ponary forest, Aba Kovner, leader of the Hashomer Hatzair youth movement in the ghetto, told an assembly of Jewish youth: “Hitler plans to destroy all the Jews of Europe, and the Jews of Lithuania have been chosen as the first in line. We will not be led like sheep to the slaughter …....