The precedent under international law established by the earlier-adopted Stimson Doctrine , as applied to the Baltics in U.S. Under Secretary of State Sumner Welles 's declaration of July 23 , 1940 , defined the basis for non-recognition of the Soviet Union 's forcible incorporation of Latvia . Despite Welles 's statement , the Baltics soon reprised their centuries-long role as pawns in the conflicts of larger powers . After visiting Moscow in the winter of 1941 – 1942 , British Foreign Minister Anthony Eden already advocated sacrificing the Baltics to secure Soviet cooperation in the war . The British ambassador to the U.S. , Lord Halifax , reported , " Mr. Eden can not incur the danger of antagonizing Stalin , and the British War Cabinet have ... agree d to negotiate a treaty with Stalin , which will recognize the 1940 frontiers of the Soviet Union . " By 1943 Roosevelt had also consigned the Baltics and Eastern Europe to Stalin . Meeting with Archbishop Spellman in New York on September 3 , U.S. President Franklin D. Roosevelt stated , " The European people will simply have to endure Russian domination , in the hope that in ten or twenty years they will be able to live well with the Russians . " Meeting with Stalin in Tehran on December 1 , Roosevelt " said that he fully realized the three Baltic Republics had in history and again more recently been part of Russia and jokingly added , that when the Soviet armies re-occupied these areas , he did not intend to go to war with the Soviet Union on this point . " A month later , Roosevelt related to Otto von Habsburg that he had told the Russians they could take over and control Romania , Bulgaria , Bukovina , Eastern Poland , Lithuania , Estonia , Latvia , and Finland . The future was sealed when on October 9 , 1944 Churchill met with Stalin in Moscow and penciled out the post-war state of Europe . Churchill recounts : " At length I said , ' Might it not be thought rather cynical if it seemed that we had disposed of these issues , so fateful to millions of people , in such an offhand manner ? Let us burn the paper . ' &mdash; ' No , you keep it , ' said Stalin . " The February 1945 Yalta Conference , widely ascribed as determining the future of Europe , essentially codified Churchill 's and Roosevelt 's prior private commitments to Stalin not to interfere in Soviet control of Eastern Europe
Yalta Conference
Yalta Conference
Soviet re-occupation of Latvia in 1944