The two books that most influenced me as a student were not by economists. One was by the US diplomat turned historian, George Kennan, entitled The Realities of American Foreign Policy. The other was by the Cambridge professor of history, Herbert Butterfield, entitled Christianity, Diplomacy and War. They appeared in the 1950s, about the time that a hawkish US secretary of state, John Foster Dulles, used to talk about “rolling back the tide of communism”.

Kennan’s target was what he called the “moralistic-legalistic” approach to foreign policy, which he maintained brought more human hardship than a straightforward defence of national interest. Butterfield approached his subject as a committed Christian. But a reader did not need to have any religious affiliation to follow his warnings about rushing to judgments that subsequently turned out to be wrong and led to more suffering than a more humble approach would have done. Their obvious targets were the doctrine of unconditional surrender that had been pursued by the allies in the second world war and the impatience of some enthusiasts to go beyond the doctrine of containment and embark on an ideological crusade against the Soviet Union.