White had supported the Progressive Party candidate in the 1924 presidential election, and, although he was probably never a member of the Communist Party, his left-wing inclinations led him to study and admire the Soviet Union. After he moved to Washington he was recruited by Whittaker Chambers to pass classified documents to Soviet agents, and this seems to have continued throughout the war. 

Chambers, who broke with the Communists in 1938, reported White's activities to the FBI, but the evidence was not strong enough to threaten his position in the Treasury or his appointment in 1945 as executive director of the IMF. Indeed, when White appeared before the House Un-American Activities Committee in 1948, he convinced the committee (though not one of its junior members, Richard Nixon) that he was an unfairly traduced, loyal American. White died of a heart attack a few days after the hearing, and the charges against him were not fully proven until some years later.

Did White's Communist sympathies affect his approach to economic policy? He favoured a low-interest loan to the Soviet Union in 1945 (it did not go ahead), and he envisaged a postwar world in which the two superpowers would work closely together. But the Soviets never ratified the Bretton Woods agreement and never joined the International Monetary Fund. At least on monetary matters, the Soviet Union was irrelevant to the struggle which absorbed most of White's energies, that between the US and Britain.

What mattered to the British was to stave off bankruptcy, to maintain the role of sterling as an international trading currency, and to preserve what they could of their imperial power. Unlike some of his critics such as Lord Beaverbrook, Keynes had no emotional attachment to the empire, but he saw it as the only bulwark against outright economic dependence on the US.