In fact, the animosity ran so deep that when both countries were no longer communist, and Russia was looking to replace its November 7 Bolshevik Revolution holiday, it came up with November 4, the anniversary of the Russian boyars’ victory in 1612 over Polish King Sigismund’s short-lived occupation of Moscow. Now there is talk, in both Warsaw and Moscow, that the second tragedy of Katyn might usher in a new era in bilateral relations.