Atlantic Charter

Roosevelt and Churchill conferred on warships in Placentia Bay on 9–12 August 1941. The result was not a signed treaty but a declaration of "common principles": no territorial aggrandisement, no border changes against the wishes of the peoples concerned, the right to choose one's form of government and the restoration of sovereignty to those deprived of it, together with freer trade and freedom of the seas. The formally neutral United States thus stood publicly beside Britain.

In September 1941 other Allies, the USSR and Poland among them, endorsed the Charter's principles, and on 1 January 1942 the Declaration by United Nations confirmed them. The Polish government repeatedly invoked the Charter in protesting against the loss of its eastern lands without its consent, but at Tehran and Yalta the powers did not treat it as binding.