Donald Duart Maclean (/məˈkleɪn/; 25 May 1913 – 6 March 1983) was a British diplomat and Soviet double agent who participated in the Cambridge Five spy ring.

In the winter of 1933–34 he wrote a book review for Cambridge Left, to which other leading communists contributed, such as John Cornford, Charles Madge and the Irish scientist, J. D. Bernal.

In one article, he insisted: "England is in the throes of a capitalist crisis....If the analysis in the Editorial: A Personal is correct, there is an excellent reason why everyone of military age should start thinking about politics.

[6] In 1934, his last year at Cambridge, Maclean became an agent of the Soviet Union's People's Commissariat for Internal Affairs, abbreviated from the Russian as NKVD recruited by Arnold Deutsch.

In October, he started work at the Foreign Office, and was assigned to the Western department, which dealt with the Netherlands, Spain, Portugal, and Switzerland, as well as the League of Nations.

"She was a cut-out between Maclean and his NKVD controller", said Geoffrey Elliott, who wrote a book about her with Igor Damaskin, a former KGB officer.

In the spring of 1939, an Anglo-French attempt was made to include the Soviet Union into the "peace front" that was intended to deter German aggression.

In October 1929, Melinda and her sisters went to school at Vevey, near Lausanne, where their mother rented a villa, and spent their holidays at Juan-les-Pins in France.

Maclean became one of the Foreign Office's experts on economic warfare, civil air matters, military base negotiations and natural resources useful in the war, such as tungsten.

The Macleans became part of the liberal Georgetown social set in Washington, which included Katharine Graham,[18][19] as well as participating in the diplomatic life of the city.

In addition to atomic energy matters, Maclean's responsibilities at the Washington embassy included civil aviation, bases, post-hostilities planning, Turkey and Greece, NATO and Berlin.

"[22] Cairo was an important post, the key to British power in the area and a central point in Anglo-American planning for pre-emptive war with the Soviet Union.

"And, except to stress its dangers, that was all I ever heard Donald say about communism," recalled Geoffrey Hoare, the News Chronicle Cairo correspondent.

[23] Maclean was considered the key official in the Cairo Embassy, specifically responsible for coordinating US/UK war planning and, under the Ambassador, relations with the Egyptian government.

After a drunken episode which resulted in the wrecking of an American embassy staffer's apartment, Melinda told the ambassador that Donald was ill and needed leave to see a London doctor.

The most important report Maclean sent to Moscow concerned the emergency summit in Washington in December 1950 between the British Prime Minister Clement Attlee and U.S. President Harry S.

The British were strongly opposed to both the use of nuclear weapons and escalating the war by attacking China, and Attlee had gone to Washington with the aim of stopping both.

The journalist Cyril Connolly vividly described what he had seen of Maclean in London c. 1951: "He had lost his serenity, his hands would tremble, his face was usually a livid yellow...he was miserable and in a very bad way.

The cryptanalysts working as part of the Venona project, discovered that twelve coded cables had been sent, six from New York from June to September 1944 and six from Washington in April 1945, by an agent named Gomer.

It suggested that Churchill was trying to persuade Roosevelt to abandon plans for Operation Anvil, the invasion of Provence, in favour of an attack through Venice and Trieste into Austria.

[29] Shortly after the VENONA investigation began, Kim Philby, another member of the Cambridge Five, was assigned to Washington, serving as Britain's CIA–FBI–NSA liaison.

[23] Maclean, unlike Burgess, assimilated into the Soviet Union and became a respected citizen, learning Russian, receiving a doctorate, and serving as a specialist on the economic policy of the West and British foreign affairs.

In February 1956, the presence of Maclean and Burgess in Moscow was publicly revealed following an interview with Sydney Weiland, a Reuters correspondent, and Richard Hughes of The Sunday Times,[31] though a statement issued by the Soviet press agency TASS denied that Burgess and Maclean had ever been spies, claiming that they had gone behind the Iron Curtain to "further understanding between East and West" for the sake of world peace.

[32] After a brief period teaching English at a school in Kuybyshev (now Samara), Maclean joined the staff of International Affairs in early 1956 as a specialist on British home and foreign policy, and relations between the Soviet Union and NATO.

He briefly shared a small room with his new Soviet colleagues on the second floor of the magazine's premises on Gorokhovsky Pereulok [ru; uk].

[38] Maclean's son, Donald, married firstly Lucy, daughter of George Hanna, an English man who worked for the BBC and was a friend of the family.

[42] He was cremated and his ashes were scattered on his parents' grave in the churchyard of Holy Trinity Church, Penn, Buckinghamshire, United Kingdom.

[citation needed] At the time of his death, Maclean had been working at the Institute, "a government think-tank, as a foreign policy analyst" according to The Washington Post.

[45] Maclean told journalists that he set out to analyse the subject rather than to attack it, but criticised British diplomatic support for the United States in the Vietnam War.

Of the five spies that made up the Cambridge Spy Ring, Maclean was not the best known, but, according to some, he provided the most intelligence of value to the Soviet Union as his position as a senior diplomat in the Foreign Office gave access to more information than what could be accessed by Philby, Cairncross, Blunt or Burgess as he was able to provide the Soviets with "the most intimate details" of Anglo-American decision-making on such matters as the future of nuclear energy and the founding of the North Atlantic Treaty Organization.