This article is devoted to the role of the British politician Harold Macmillan in the Suez Crisis of 1956. Based on British archival documents and MacMillan's personal diary, this article recreates a double game played by the head of the Treasury. Harold Macmillan belongs to the number of British politicians whose biographies have many "white spots", carefully hidden by themselves and their surroundings. One of these gaps is the activity of Macmillan as the Chancellor of the Exchequer during the Suez Crisis of 1956. From the very beginning of the aggravation of the situation in the Middle East, caused by the nationalization of the Suez Canal Company by the Egyptian government of Gamal Abdel Nasser, Macmillan advocated for a military operation against Egypt. Moreover, he was the first who proposed to involve Israel in this operation in the summer of 1956. The hesitation of the British Prime Minister Anthony Eden, who was afraid to start military actions in the Middle East without the support of the United States, did not suit the head of the British treasury. In order to convince Eden of the need to start a forceful operation against Egypt as soon as possible, Macmillan distorted the information about the negotiations that he held at the end of September 1956 in Washington with the US President Dwight Eisenhower and the Secretary of State John Foster Dulles. The American allies of London were not against overthrowing Nasser, but insisted that military actions in Egypt should not start before the presidential elections in the US. Macmillan presented the latter condition as optional, emphasizing the readiness of the United States to support the military operation against Egypt. The start of the aggression against Egypt in the midst of the election campaign in the US caused irritation in the administration of Eisenhower. According to Macmillan, the United States threatened to stop financial aid to Great Britain, which forced the latter to end the military operation in the Suez Canal zone. However, there is no other data on the American pressure, except for the words of the Chancellor of the Exchequer, repeated later in his memoirs. All this allows ranking Harold Macmillan among the number of the main architects of the Suez Crisis, skillfully combining the implementation of the imperial line of behavior with his own political calculations.