The Welles Declaration was a diplomatic statement issued on July 23, 1940 by Sumner Welles, the United States' acting Secretary of State, condemning the June 1940 occupation by the Soviet Union of the three Baltic states of Estonia, Latvia and Lithuania, and refusing to recognize their annexation as Soviet Republics. It was an application of the 1932 Stimson Doctrine of non-recognition of international territorial changes that were executed by force. It was consistent with U.S. President Franklin D. Roosevelt’s attitude towards territorial expansion.
The Soviet invasion was an implementation of its 1939 Molotov-Ribbentrop Pact with Nazi Germany, which contained a secret protocol by which the two powers agreed to partition and annex the independent states between them. After the pact, the Soviets engaged in a series of ultimatums and actions ending in the annexation of the Baltic states during the summer of 1940. While the area held little strategic importance to the United States, several legations of the U.S. State Department established diplomatic relationships there. The United States and Britain anticipated future involvement in the war, but U.S. isolationism and a foreseeable British-Soviet alliance deterred open confrontation over the Baltics. Welles, concerned with postwar border planning, had been authorized by Roosevelt to issue stronger public statements gauging a move towards more intervention. Loy Henderson and other State Department officials familiar with the area kept the administration informed of developments there, and Henderson, Welles, and Roosevelt worked together to compose the declaration.