Archibald Mackenzie: Diplomat whose work helped establish the United Nations

Archie Mackenzie was one of Britain's less orthodox diplomatic servants and probably the last surviving delegate to have been at the founding of the United Nations at Dumbarton Oaks and San Francisco in 1945.

He entered the service while a postgraduate student in the US on the eve of the Second World War, and would find himself in many key situations. He was at one stage investigated for disloyalty because of his religious activities and yet, observers said, he brought about more compromise solutions than any other diplomat.

Over 32 years, the Scot who had never set foot in England or the continent until he was 18 saw service in Burma, Cyprus, France, Thailand, Yugoslavia and the US. Into his late 80s, he was still working for the reconciliation of conflicts in the Middle East and Africa.

Mackenzie believed deeply that the UN needed a moral and spiritual dynamic to help it deal with such basic human weaknesses as hatred and cynicism, corruption and egotism, and to enable it to tap into higher sources of wisdom: "And of course in such a spiritual odyssey there is another categorical imperative that applies: Everyone must start with themselves." He famously said that at international conferences the problems sitting round the table were often more resistant to change than those on the table.

Archibald Robert Kerr Mackenzie, or Archie, as he was known, was born in 1915 in a Glasgow tenement and attended Bellahouston Academy. At Glasgow University he achieved first-class honours in philosophy and went on to Oxford with a scholarship. In 1939 he gained a Harkness Commonwealth fellowship to the University of Chicago to study "The ethical implications of democracy with special reference to the work of Moral Re-Armament".

In 1940 Mackenzie transferred to Harvard but was offered a post at the British Embassy. A unit had been assembled to provide London with information about the American scene and to help London disseminate corrective information inside the US. Mackenzie's boss was Isaiah Berlin, whose weekly political summary was considered essential reading in Whitehall by everyone from Churchill down. For three exciting years as news-gatherer, recorder and editor he was Berlin's amanuensis.

In 1944 he was at Dumbarton Oaks where the blueprint for the UN was prepared, and in 1945 he set up the press office for the San Francisco conference. The New York Post said: "Mackenzie has become celebrated as the author of more good news breaks than any other single source in the United Nations corral. If something was going on, standard operating procedure was to 'get Archie'. Because if Archie knew and he could tell, and usually he knew and could, the story made the next edition."

In 1945 he was called to London to work on the UN Charter and on the UN Headquarters Commission and the London Assembly, becoming First Secretary in New York. Of his work on the UN Subcommission on Freedom of Information 1948 in Geneva, The New Republic wrote, "Mackenzie is easily the ablest man on the subcommission despite the fact that he was called in at the last minute. He has been responsible for more compromise solutions than anybody else and his quick perception has saved days of work."

He joined the Foreign Office in 1949 and in 1951 went to Thailand as First Secretary. In his memoir Faith in Diplomacy he wrote, "I would have difficulty in saying whether my desk activities or my extra-curricular activities – contacts with the Buddhist world, academia, royal circles, etc – were more significant, in fact, they merged time and again, and the one sure thing is that the policy-makers in the Foreign Office received a much richer stream of information about trends in Thailand than they might have anticipated."

In 1954, he went to Cyprus to face "a most tricky challenge; how to inject into our official circles in London as well as Nicosia that our own policies needed reviewing". In 1957 he was with the OECD in Paris, where he met Ruth Hutchison, the daughter of a Glasgow businessman. They were married in 1963, and the same year he was sent to Burma as commercial counsellor.

After serving as Consul General in Zagreb he was made Ambassador to Tunisia in 1970. For his last three years of service he was Minister for Economic and Social Affairs to the UN. During the Seventh Special session, he introduced an unexpectedly cooperative note when he spoke of the need to "cross the philosophical bridge of change". This caught the attention of delegates, and was often quoted in the subsequent months. At the end of the session, one delegate said of Mackenzie: "With him arrived a new spirit and a new attitude."

On retirement he worked with the Brandt Commission as assistant to the former Prime Minister Ted Heath. He had been introduced to the Moral Re-Armament movement at 18 and found in it, he said, a "channel to a more living faith". This association with MRA (now known as Initiatives of Change) brought an extra dimension to his diplomatic life – "and in particular introduced me to the concept of a daily time of moral and spiritual meditation which changed my life-style and remained a regular habit early every morning."

At one point he was told that the Foreign Office disapproved of his association with MRA and that unless he renounced it could expect no further promotion. He appealed to the Foreign Secretary; he had never been faulted by the ambassadors he had served, and eventually the critical reports were removed from his file. In his memoir Mackenzie wrote, "I met opposition from time to time. But I also found repeatedly that, when facing difficulties, an ally would appear or a locked door would open."

Reflecting on the future of the UN and the rise of ethnic tensions, he wrote, "There may be no perfect antibiotic to rid us of ethnic fevers. Safety may lie in the realisation that we all have multiple loyalties and we all contain contrary genes in our make-up. Even the Mackenzie clan is known across Scotland for contending reasons. On the one hand the motto is 'Save the King' ... But in parallel there is another less respectful Gaelic saying, 'You'd better beware of the Mackenzies as long as their bellies are empty.'"

Michael Henderson

Archibald Robert Kerr Mackenzie, diplomat: born 26 October 1916; Ambassador to Tunisia, 1970-73, Minister for Economic and Social Affairs, United Nations 1973-75; CBE 1967; married 1963 Ruth Hutchison; died Rowardennan, Stirling 15 April 2012.