Relations between the USSR and the Baltic Countries. September 1939 – May 1940
In the conditions of escalating war, the Soviet leadership began to expand its influence in the Baltic region in order to oppose German expansion. Inviting representatives of the Baltic states to Moscow, the Soviet government signed mutual assistance agreements with Estonia (September 28, 1939), Latvia (October 5, 1939) and Lithuania (October 10, 1939), allowing the USSR to build military and naval bases in these countries to repulse aggression. the agreement with Lithuania also stipulated the return of the city of Wilno (the present-day capital city of Vilnius) and the Wilno Region to the Lithuanian Republic, both of which had previously passed to Poland as a result of the Polish-Lithuanian conflict.
The procedures for the dislocation and accommodation of small Red Army units in the Baltic states were set down in supplementary agreements. the Soviet troops were categorically prohibited from interfering in the internal affairs of the sovereign Baltic states and promoting the Sovietization of the republics.
Although the Estonian, Latvian and Lithuanian governments signed the mutual assistance agreements, they had no intention of fully respecting their terms. the ruling elites of the Baltic states preserved secret ties with Nazi Germany and hardly masked their hostility towards the Soviet Union. Provocations were prepared against military objects of the Red Army and the Baltic Fleet, and plans were made to obstruct and destroy them. the idea of ‘driving the Soviet troops into the sea’ was advocated in Latvia, volunteers were recruited in Estonia to fight against the Red Army in the Soviet-Finnish conflict, while members of the Lithuanian establishment openly expressed their hopes of driving the Bolsheviks out of the country.
Instances of the political disloyalty of the governments of Baltic states and their readiness to violate the mutual assistance agreements were well known to the Soviet leadership.