1917 - Lenin repudiated all Tsarist foreign debts and froze all foreign assets in Russia
1918 - The Treaty of Brest-Litovsk ended the war with Germany, and despite the harsh terms, guaranteed the survival of both Russia and the Bolsheviks.
1919 - The Communist International (Comintern), a Soviet-led organisation of the Communist Parties of all countries, was established to provide support to foreign left-wing groups and promoting revolution
1922 - The Treaty of Rapallo represented a non-ideological approach to foreign policy and gave Russia a place for her exports as well as opening the door for Russian entry into international affairs. More importantly, though, it was aimed at ensuring the survival of the Soviet Union
1925-1932 - "Peaceful co-existence". A series of neutrality treaties were signed with Turkey, Germany (Treaty of Berlin), Lithuania, Afghanistan, Iran and Finland.
1928 - The Kellogg-Briand Pact was a symbolic treaty that outlawed war
1933 - Soviet foreign policy became concerned with avoiding isolation and finding allies to nullify the German danger.
1934 - The USSR joined the League of Nations in an effort to promote collective security.
1936-1939 - The Spanish Civil War saw Stalin provide limited assistance to the socialist government in the hope of diverting attention away from his purges
1938 - The Munich Conference was viewed by Stalin as a gathering of anti-Soviet nations, intent on giving Germany permission to attack on the isolated Soviet Union
1939 - The Nazi-Soviet Non-Aggression Pact provided Stalin with 'breathing space' so that the could build up Soviet defences (those which he had purged in the great terror). Furthermore, the treaty restored the international losses of 1918 and divided Poland between the two nations.
1939 - Two weeks after Hitler attacked Poland, Soviet armies occupied the eastern half, and in June 1940, the USSR occupied the Baltic states of Latvia, Estonia and Lithuania.
1941 - Nazi Germany invaded the USSR.