Following the Soviet invasion of the Baltic states in June 1940, repressive measures were enforced in these countries, including arrests, executions and mass deportations, in accordance with the Serov Instructions.
After the German occupation, the Soviet Union reoccupied the Baltic states from 1944, sparking several years of armed resistance from groups like the Forest Brothers.
At the end of the 1980s, as the influence of the Soviet Union decreased, peaceful demonstrations known as the Singing Revolution in the Baltic states ultimately led to their independence.
[1] The Stalinist Soviet regime initiated a constitutional metamorphosis of the three Baltic states by first forming transitional "Peoples Governments.
[4] All non-Communist controlled public activity was proscribed, while political, social ideological and religious groups which could be subsumed into the Communist fronts were disbanded, including even the Boy Scouts.
Public tribunals were also set up to punish "traitors to the people": those who had fallen short of the "political duty" of voting their countries into the USSR.
[13]: 48 According to historian Robert Conquest, the selective deportations from the Baltic States represented the policy of "decapitation" of the nation by removing its political and social elite, "as was later evidently to be the motive for the Katyn massacre.
[17] The reconstituted parliaments quickly proclaimed the nationalization of large industries, transportation, banks, private housing, and commerce in general.
[13]: 46 By creating large numbers of small, nonviable farms, the Soviet regime intended to weaken the institution of private landholding so that later collectivization, a program of agricultural consolidation that was undertaken in the USSR a decade earlier, could be presented as an efficient alternative.
The Forest brothers, as they were known, enjoyed the material support among the local population[citation needed], as well as from the British (MI6), American, and Swedish secret intelligence services.
10 percent of the entire adult Baltic population was deported or sent to labor camps,[12] effectively breaking the back of the insurgency.
[27] In July 1989, following the dramatic events in East Germany (the fall of the Berlin Wall), the Supreme Soviets in each of the Baltic countries adopted a "Declaration of Sovereignty" and amended the Constitutions to assert the supremacy of their own laws over those of the USSR.
The United States, which had never recognized forcible annexation of the Baltic countries by the USSR, resumed full diplomatic relations with the republics.