Balfour saw the matter rather differently. ‘His political bête noire,’ Adams tells us, ‘was Sir Robert Peel, whose conversion to Free Trade in 1846 had broken the Tory Party over an economic principle he believed more important than party unity.’ To use another analogy, he was a Harold Wilson to Chamberlain’s Ted Heath: a pragmatist who believed that nothing mattered very much and certainly nothing mattered more than keeping his Party in power as opposed to a man who held passionate convictions and would not hesitate to destroy the Party rather than abandon or even temper them. More often than not pragmatism works; this time it did not. Balfour allowed his government to disintegrate and opened the way for the great reforming Liberal administration of Asquith and Lloyd George.

His career was far from over, though, for he was in and out of office for another 20 years. What he is above all remembered for is the Balfour Declaration of November 1917, in which he pledged the British Government to support the setting up in Palestine of ‘a national home for the Jewish people’. The positive side of this —- a fierce opposition to anti-Semitism and a recognition of the historical and cultural heritage of the Jews — was admirable, but though the Declaration contained a cautious proviso about defending the ‘civil and religious rights of existing non-Jewish communities in Palestine’ Balfour never realised what problems he was creating for future generations. ‘It will require tact,’ he said in 1922, ‘it will require judgment, it will require above all sympathetic goodwill on the part of Jew and Arab.’ If Arab Balfours had faced Jewish Balfours the tact, judgment and good will would have been there in plenty, but Balfours were hard to find in the Middle East and would probably have lasted only a few weeks if they had existed.

Adams is one of those disconcerting Americans who know as much about British history as any Briton. He writes with grace, intelligence and concision. Max Egremont’s biography of 1980 is unbeatable as providing the insider’s picture of Balfour; this excellent book presents the external view. Perhaps Adams might follow it by writing a one-volume study of Lloyd George to complement John Grigg’s magnificent but sprawling biography.

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