For the first mile or so Christopher Mallaby walked and stumbled through a maze of British rocks and puddles into the still raw and unfinished Channel tunnel. Then he got on to a makeshift buggy for the next 35 miles. The final mile he completed on foot to emerge in Calais as the new British ambassador to France. It had been Christopher’s idea to inaugurate his ambassadorship there in 1993 by becoming the first diplomat ever to make a land journey from Britain to the European mainland.
Christopher, who has died aged 85, was one of Britain’s pre-eminent postwar diplomats. From 1960 to 1996 he was at the centre of diplomatic activity surrounding the end of the cold war and German reunification.
Fluent in French, German and Russian, he was a fledgling diplomat in Moscow during the Cuban missile crisis in 1962. He was back in Moscow in a senior position from 1975 to 1977, a period when the adoption of the Helsinki accords was beginning to help east-west relations, and from henceforth always landed in the right postings, either in the Russian capital, London or Bonn – later moving to Berlin – to help steer British policy as cold war tensions eased.
As British ambassador (1988-92) in what was initially West Germany when the Berlin Wall came down, Christopher was an early convert to reunification and had the courage to be blunt with Margaret Thatcher over her unrealistic opposition to a united Germany. He battled hard to reconcile her to that inevitability, which, when it came in 1990, prompted crucial discussions about the future role of Nato.
In his memoir, Living the Cold War (2017), he gave an account of the diplomatic manoeuvring at that time, which Vladimir Putin is now exploiting to justify Russia’s invasion of Ukraine. Christopher wrote that the US secretary of state, James Baker, “told Mikhail Gorbachev in early February 1990 that the borders of Nato would not move further eastward than united Germany. He offered a guarantee on this on the assumption that Gorbachev would agree that Nato would continue to exist and US forces would be stationed in Europe under Nato.” Christopher added that Helmut Kohl of Germany and the then prime minister, John Major, gave the Russians a similar undertaking.
However, the US president, George HW Bush, “immediately decided that this undertaking should not be made”. Gorbachev did not ask for a written record of these exchanges and the way was left open for dangerous controversy. As he observed at the time of his memoir, “a truculent Putin and the Russian people now see themselves as surrounded by a truculent west … and believe that the west wants to add Ukraine to Nato”.
While Christopher recognised the dangers of expanding Nato into the Baltics and eastern Europe, he nevertheless concluded it would give them essential security guarantees against Russia.
Born in London, Christopher came from a military family and was only nine years old when his father, Maj Gen Aubertin Mallaby, was assassinated in Indonesia. His mother, Margaret (nee Jones), his brother, Anthony, and sister, Sue, were left in straitened circumstances, but both boys were awarded bursaries to go to Eton.
After a stint of national service that took Christopher for his first extended stay in West Germany, he spent three years at King’s College, Cambridge, initially studying French and German before turning to modern history.
The army experience taught Christopher that he did not want to follow in his father’s footsteps. In search of another form of public service, he turned to the Foreign Office, where in 1959 he passed the entrance exams with flying colours. He had found his metier.
He had also found the love of his life, Pascale Thierry-Mieg, and they married shortly before going to Moscow in 1961.
His first contact with cold war diplomacy came in 1960, when he was posted to the United Nations during the general assembly, where east-west tensions were on full display. He continued to be in the right place as a 23-year-old junior in Moscow, when he was conveniently at hand to replace an interpreter during a British businessman’s conversation with the Soviet leader, Nikita Khrushchev.
He was London-based as head of policy planning (1980-82) when he was asked to coordinate Foreign Office work on the Falklands crisis and had his first direct contact with Thatcher. He worked with the prime minister again during the negotiation of the 1985 Anglo-Irish agreement.
The three years of his final posting, as ambassador in Paris, gave him ample scope for promoting Anglo-French cooperation. He had considerable access to presidents François Mitterrand and Jacques Chirac, and a kaleidoscopic cross-section of French society was invited to the palatial embassy. The former health minister and Auschwitz survivor Simone Veil became a close friend. Pamela Harriman, the US ambassador, would slip through the garden gate between the two embassies for informal chats.
Christopher was managing director of what became UBS Investment Bank (2000-06), had a four-year term as chairman of Somerset House Trust, and six years as a trustee of the Tate. He also served as deputy chairman of Reuters (1998-2013), and chairman of the European Organisation for Research and Treatment of Cancer (2001-13).
Knighted in 1996, he made lasting friendships in every post. “I loved almost every moment of my career,” he wrote in his memoir.
Pascale died in 2020. Christopher is survived by a son, Sebastian, and three daughters, Emily, Julia and Charlotte.
• Christopher Leslie George Mallaby, diplomat, born 7 July 1936; died 28 February 2022
