Empire: During the second World War, as Churchill's point man on Eisenhower's team in Algiers, Harold Macmillan observed that Britain must inevitably come to play the role of latter-day Greeks to the US's Romans.
Just as the Romans superseded the Greeks whilst at the same time drawing on their culture, wisdom, and knowledge, so the US too would surpass Britain's empire but still rely on British judgment and support. Or as Lord Halifax said to Lord Keynes after the war: "The Americans have all the money, and we have all the brains."
Colossus, Niall Ferguson's characteristically provocative new book, also suggests that the US must look to the example of the British empire as it struggles with the burdens of being the world's number one power.
"The relationship between the two Anglophone empires is one of the leitmotifs of this book," writes Ferguson, "for the simple reason that no other empire in history has come so close to achieving the things that the United States wishes to achieve today."
Niall Ferguson, Herzog professor of financial history at the Stern School of Business in New York, is the latest British historian to be fêted in America. In each generation, the brightest and best are lured across the Atlantic at vast expense to offer a view from the Old World. In the 1980s Paul Kennedy's blockbuster, The Rise and Fall of the Great Powers, was required reading in the Reagan White House. In the 1990s Columbia made Simon Schama the world's best-paid historian on a reputed $1 million salary. Now Ferguson has brilliantly taken up the mantle of Britain's leading public intellectual and controversialist in the US.
Colossus is Ferguson's most trenchantly polemical book to date. He argues, in short, that empire is a good thing, and that the US should not only accept its imperial role, but must for all our sakes embrace it.
"I am fundamentally in favor of empire," he writes in the introduction. "Indeed, I believe that empire is more necessary in the 21st century than ever before."
This is typical Ferguson, who has made a habit of turning conventional wisdom on its head, but he spends the next 350 pages making a credible argument that empire has and would make the world a happier, more ordered and prosperous place. But what Ferguson admires is not just any kind of empire, but a "liberal empire" that promotes free trade, the rule of law and social progress. The benchmark here is the British who, "after the mid-19th-century calamities of the Irish Famine and the Indian Mutiny, recast their empire as an economically liberal project, concerned as much with the integration of global markets as with the security of the British Isles, predicated on the idea that British rule was conferring genuine benefits in the form of free trade, the rule of law, the safeguarding of private property rights and non-corrupt administration, as well as government-guaranteed investments in infrastructure, public health and (some) education".
Compare this with the dismal record of failure in the post-colonial world since 1945, and the argument for a new imperialism begins to make sense. Relatively few former colonies have achieved prosperity. In regions such as sub-Saharan Africa decolonisation has been followed by persistent conflict between newly independent states or, more often, within them. Neither has decolonisation created much democratic dividend, more often producing dictatorship.
"Many of these dictatorships have been worse for the people living under them than the old colonial structures," Ferguson writes, "more corrupt, more lawless, more violent."
Convincing us of the benefits of the British empire - always a hard sell in Ireland - is a job for Ferguson the historian. But for significant parts of this book, he also engages in contemporary political debate, urging the US to embrace the imperial model or perish. Yet while neo-Conservatives such as Max Boot believe that the likes of Afghanistan and Iraq cry out for the sort of "enlightened foreign administration once provided by self- confident Englishmen in jodhpurs and pith helmets", most in the American establishment recoil from any suggestion that they might be new imperialists.
"We've never been a colonial power," said defense secretary Donald Rumsfeld recently. "That's just not what the United States does."
Ferguson is a self-confessed admirer of American values and systems, but is scathing in condemning its failure to embrace an imperial destiny.
"The United States has acquired an empire, but Americans themselves lack the imperial cast of mind," he writes disdainfully. "They would rather build shopping malls than nations. They crave for themselves protracted old age and dread, even for other Americans who have volunteered for military service, untimely death in battle."
Carry on like this, he warns, and the American empire will "unravel as swiftly as the equally 'anti-imperial' empire that was the Soviet Union."
Colossus is yet another tour de force from a writer who displays all his usual gifts of forceful polemic, unconventional intelligence, and elegant prose. It is guaranteed to spark fierce public debate on the nature of empires and the direction of the US's overseas policy. Whether Ferguson turns out to be right will depend, as Harold Macmillan also said, on "events, dear boy, events".
• Richard Aldous's Gladstone and Disraeli will be published by Hutchinson next year. His biography of Malcolm Sargent is available in Pimlico paperback