As Foreign Secretary from 1935 to 1938, he was noted for his support for the League of Nations: he resigned over his opposition to appeasement but was again Foreign Secretary from 1940 to 1945 and from 1951 to 1955. He was also deputy leader of the Conservatives (1945–55) under Churchill, whom he succeeded as Prime Minister. Eden’s premiership was dominated by the Suez War. Owing to his experience of appeasement, he was determined to stand up to President Nasser of Egypt, whom he perceived as a potential aggressor. Widespread opposition to Britain’s role in the Suez Crisis, together with his own failing health, led to his resignation.