For the last century the Empire has been in decline, first slowly, and then, after the Second World War, rapidly. The name "Empire" went 50 years ago; most of the colonies followed in the 1960s. The return of Hong Kong to Chinese rule marks the (almost) definitive end, however, reducing the population of British-ruled territories abroad to less than 200,000: just fly-specks on the map.
Yet this process, a momentous change by any historical standard, has stirred remarkably little emotion, interest even, in Britain. There is a kind of silence.
The silence is partly the result of a positive factor: the widespread lack of imperial nostalgia in Britain. Despite the fact that we sometimes seem to the outside world to be perpetually looking backwards, there is very little sense of loss in Britain. For France, decolonisation was often painful and bloody, notably in Indo-China and Algeria; and it continues to be a painful subject.
Yet this silence is also the result of a negative factor: the lack of systematic consideration at any point of what should come after Empire. Douglas Hurd could still speak about punching above our weight in the 1990s; the Royal Navy has this year sent a massive flotilla half way around the world to prove it can still project force into the South China Sea; we have a permanent seat on the United Nations Security Council, nuclear weapons, and intelligence services designed to maintain a global presence on budget terms. What is all this for? The end of Hong Kong as a British base and a British strategic interest makes a serious rethink all the more timely.
The lack of any clear strategic thought about Britain after Empire masks a deeper silence: the silence that comes when a piece of music is over. The anthem of Empire has provided the background music to British politics, culture and life since James Thomson composed Rule, Britannia in 1740. It was used as a cement to keep the Union alive at home, and to create the very idea of Britishness, as Linda Colley showed in her book Britons. It played a seminal role in the creation of the modern Conservative Party - Disraeli wielded it to devastating effect in his Crystal Palace speech of 1872, when he set out the tasks of the party as to "maintain our institutions, to uphold the Empire and to elevate the condition of the people". Margaret Thatcher showed she could whistle it when she urged us to "Rejoice! Rejoice!" in 1982. As monarchy and Empire have faded away together, so the foundations of the Conservative party have looked ever shakier.
It was not so much that Empire and the imperial experience was dominant; but that it coloured so much of life, from food to music to the English language. It was all-pervasive. Now, that music has come to a definitive end - this time there are no repeat marks at the end of the score. And yet there is no persuasive anthem to replace it.
One theme that is whistled on the right of the Conservative Party is a kind of new Elizabethanism: we should cut loose from Europe, and explore the opportunities open to a medium-sized nation-state in the open global environment of the 21st century. A second tune harmonises with the European orchestra: we should submerge our identity further into the European Union. Yet another, from the left, is to aim for a kind of Swedish solution: disengage from the military alliances, reduce the armed forces, and concentrate on doing good through aid and the occasional bit of peace-keeping.
Tony Blair has come up with a lot of ideas in the past few weeks, which go some way to creating a new vision of British society; but there is no overarching vision of the place that community will hold in the world. There is a dash of Euroscepticism here, some Europhilia there, the somewhat vague idea of a moral foreign policy and the occasional piece of flirting with the sense of nation - but nothing broader. Sometimes he seems as if he will return to an older, 19th century liberal policy of non-engagement; at others, as if he is grasping for a new synthesis. It is unformed so far.
There is a third kind of silence, or at least there should be: the sound of a pause for reflection about the kind of nation that Empire has made us, the things that we have as a community been involved in. It is still too soon after the whole thing to make a serious judgement; the curtain has only just come down. Some see the imperial idea as the root of much that is wrong and immoral in British society - racism, the centralised state and violence. Its disappearance clears the way to think forward, and beyond the deliquescent tumours of 19th century imperialism.
Others see it as a positive thing. Jan Morris, one of the most poetic exponents of the attractions of Empire, saw in it "a ripple in some cosmic urge to reconciliation", a part of that tide in human affairs that has helped to create a more global community. "The arrogance of Empire, its greed and brutality was energy gone to waste: but the good in the adventure, the courage, the idealism, the diligence had contributed their quota of truth towards the universal fulfilment."
Britain has achieved much that is good in its former colonies: building roads, introducing modern government (and sometimes democracy), and opening economies in the name of Christianity, liberalism and progress. It has also murdered, destroyed and betrayed - in the name of the same values. Perhaps it is no accident that when the Arabs speak of someone with an English face, they mean a hypocrite; and that much of the world, including many in Hong Kong, will remember us as Perfidious Albion, an inheritance of Empire that will outlive all of us.