ENIn the period between the two World Wars, Soviet and German diplomacy stayed in close and productive co-operation with respect to the Baltic states. They held frequent consultations on the co-ordination of policies concerning Baltic states and Poland, co-ordinated anti-Baltic and anti-Polish political-diplomatic actions, closely followed developments of the international situation in these countries, and discussed potential ways and scenarios of achieving the two country’s goals. The issue of the division of the spheres of influence in Poland and the Baltic states came to the floor of Soviet and German diplomatic discussion as early as in mid 1920’s. We must agree with the opinion, that the unilateral guarantees extended by Great British to Poland in 31 May 1939, rather than serving its security, created a broad scope for action and freedom of manoeuvres to J.Stalin and the Soviet Union. After N.Chamberlain’s declaration Moscow did not only retain the possibility to join the Western Powers, which London and Paris wereso fervently looking to and hoping for. It also played into Moscow’s hands an iron argument to open negotiations with Berlin, which could be concluded with a contract satisfactory for both parties. In the other words, the path leading to the rapprochement of the USSR and Germany, to the Ribbentrop-Molotov Pact and its secret protocols, was open. Ribbentrop-Molotov Pact and its secret protocols, was open. To avoid war on tw'o fronts, on 23 August 1939 Germany concluded a Non-Aggression Treaty with the Soviet Union. Alongside the Treaty, a secret additional protocol was drawn up envisaging that Estonia and Latvia shall belong to the USSR, while Lithuania was „allotted” to the German sphere of influence. When Germany and USSR were about to finish the defeat of Poland, on 28 August 1939 they entered into one more political agreement concerning friendship and borders.According to the secret protocol attached to this agreement, Lithuania was handed over to the Soviet Union’s sphere of influence. Soon after that, the USSR started implementing the contens of the secret agreements with Germany. On 10 October 1939, in the climate of Soviet political blackmail and threats with military power, Agreement on the Transfer of Vilnius and Vilnius Region to the Republic of Lithuania and Mutual Assistance between Lithuania and the Soviet Union was signed in Moscow. The agreement entitled Moscow to deploy its military gamisons, the contingent of 20.000 Red Army troops, in Lithuania. As a consequence of that, the Republic of Lithuania, as well as its Northern neighbours Latvia and Estonia, lost their neutrality, to a great extent, sovereignty, and, in fact, were made protectorates of the USSR. On 15 - 17 June 1940, making use of the particularly complicated international situation in Europe, the USSR handed in ultimatums to Lithuania, Latvia and Estonia and occupied them. Occupation of Lithuania by the oviet Union in 15 June 1940 was a clear violation of the international law, its international obligations as well as the following bilateral agreements with the Republic of Lithuania: 12 July 1920 Lithuanian - Russian Peace Treaty, according to which Russia relinquished the sovereign rights to Lithuania „for ever”; 28 September 1926 Lithuanian - Soviet Union Agreement on Non- Aggression and Neutrality, which was to be in force until 31 December 1945; 5 July 1933 Convention on the Difinition of Aggression which, in principle, prohibits any kind of aggression and assault; 10 October 1939 Agreement on the Transfer of Vilnius and Vilnius Region to Republic of Lithuania and Mutual Assistance between Lithuania and the Soviet Union.