Theodore Roosevelt

 was a President of the United States. His waxwork replica appeared in Madame Tussauds when the Third Doctor and Liz Shaw visited to investigate the first Auton invasion of Earth. (TV: Spearhead from Space)

In 1944, Graham Greene went on a drunken rant about his pessimistic belief that civilisation had not been saved by Theodore Roosevelt or Winston Churchill. He claimed that "The gloom, degradation and purgatory of the postwar era will in time make the war seem almost an indulgence." (PROSE: The Turing Test)

Behind the scenes
Of all the presidents on the tableau at Madame Tussauds, Roosevelt is the least obvious. He's very briefly seen in the gap between JFK and Nixon.

It is possible that Paul Leonard, the writer of The Turing Test, meant to refer to Franklin D. Roosevelt instead of Theodore Roosevelt. (The two presidents were, in fact, related.) This could be a slip of the tongue by Graham Greene from an in-universe perspective.