TALLINN, Estonia — In the summer of 1982, President Ronald Reagan declared that the United States would observe “Baltic Freedom Day.” The proclamation turned a grim anniversary — the Soviet Union’s mass deportation of Estonian, Latvian, and Lithuanian nationals away from their historic homelands began on June 14, 1941 — into an occasion to affirm “our hope that the blessings of liberty will one day be part of the national life” of three European peoples oppressed by Kremlin despots. That gesture, among many other policies, helped to secure for Reagan the admiration and affection of Central and Eastern European nations in the decades after the fall of the Berlin Wall.