A spiky and contentious figure in his prime, Donald Rumsfeld is beginning to fade into history. But he deserves to be remembered for one remark. The most important political phrase of the 2000s, it retains its power today: "the unknown unknowns".
The déformation professionnelle of political journalists is over-excitement: becoming carried away by the dramas of the day and failing to see them in perspective. Even allowing for that, I find it hard to think of a time when everything was so uncertain. The best comparison would be the period from 1931 until about 1950, when Europe seemed trapped in the valley of the shadow of death. We must hope that our problems turn out to be less serious. But there is no guarantee of a benign outcome.
In one respect, we are vastly better off. Democracy has prevailed. That said, there is an increasing disjunction between the political elites on the continent, most of whom still look to Brussels and Strasbourg, and their electorates. There are two basic difficulties. The first is dishonesty. Those who were determined to build a united Europe regarded themselves as the custodians of morality and the protectors of the future. But they were never sure whether their voters would agree. So they decided to proceed by deceit, on the assumption that one day, the peoples would salute the wisdom of the Euro-protectorate. There is an appropriate name for that day: the Greek Kalends.
The second is economics. It usually is; it's the economy, stupid – another valuable American import. I once described China as a growth-ocracy; the government earns consent and to some extent legitimacy by ensuring economic growth and higher living standards. But why only China? In the opinion of most voters, economic growth is the first duty of government. When it is not delivered, governments usually lose elections. When there is still no delivery, there is a risk of a withdrawal of consent from the entire political system: not healthy.
"Storms in the Channel: Europe cut off". At times, most of us wish: "if only". The culture, the cuisine, the landscape: we revere our continent and its history. Politically and economically, however, it can often seem as if we were tied to a sick animal. Yet there is one advantage in Europe's weaknesses. They ought to make us grateful that we do not fully share them. There is plenty of grumbling about Mr Cameron at the moment, not least in his own party. But a little perspective would be useful, to remind the malcontents that there is no abler or stronger leader in any major country.
What should our PM do to make that a more widely-held view? There is no quick solution, and some of the proposals are contradictory. A number of wise elder figures have complained that Mr Cameron is too promiscuous, with too many interviews and media appearances. Although that is a fair criticism, he is also the government's best performer. Even so, he ought to ration the performances, while dealing with another group of critics: those who insist that they still do not know what David Cameron stands for. That, of course, is always a hard question for a thoughtful Tory to answer. It was easy for old-fashioned Socialists. They had a secular teleology; they were in business to re-shape man and re-make history, in order to create socialism.
There is no Tory equivalent, only an unending dialectic between principles and opportunities. We Tories have no Nirvana. Bound to the wheel of existence in a fallen world, we can only find our inspiration in the challenges which it throws up: "The fascination of what's difficult" in Yeats's words. Before that sounds too exhilarating, remember the next lines: "Has dried the sap out of my veins, and rent/ Spontaneous joy and natural content/ Out of my heart". Toryism is not a vocation for the self-indulgent.
It follows that a general statement of Tory principles which is not anchored in a context can quickly sound self-indulgent, like an endless obeisance to motherhood and apple-pie. Even some of our greatest maxims have their hazards. "When it is not necessary to change, it is necessary not to change". That tells us everything we need to know about House of Lords Reform and homosexual marriage and, indeed, about altering the order of succession to the Throne. But the real question remains unanswered. How can we work out when it is necessary to change? Burke was right about the American Revolution and the French Revolution, not because he had a general theory of revolutions, but because he was good at getting things right. That is an example which every Tory should wish his leaders to emulate.
Even if Mr Cameron has not faced challenges of that order, he is good at getting things right, and anyone who has not formed a general impression of his cast of mind has not been looking and listening. That said, the PM could do more to project himself, though not by giving his version of a Tory two-penny catechism. Our forbears used to talk about the condition of England question. Amended to read Britain, it is still a useful short-hand for all the anxieties which voters have about the state and direction of the country: justified anxieties. Mr Cameron ought to address them, in deeper notes and in the sombre tones which do not come naturally to him, but which he does well.
As for everyday agitations, all governments need a Minister for the Today programme. That was the role which Michael Heseltine performed for John Major, so successfully that he received the accolade of an admiring Private Eye cover. A bubble asked him, as if he were giving his voice level in a studio, "What did you have for breakfast today, Mr Heseltine?" His answer: "John Humphrys". A young Hezza, or a young Norman Tebbit, would be useful. But you can never just pluck politicians of that calibre off the shelf.
There is one other current complaint, the legislation issue, on which there are also contradictory responses. Apropos of promiscuity, all Tories believe that governments legislate too much. David Cameron himself has said that no Tory ought to think that we could legislate our way to utopia. So it might seem desirable to have a government that is not intending to add more volumes of statute to the already unconsionable excesses of modern law-makers. But there is an obvious danger. Because we have all grown so addicted to incessant Bills and Acts, any government which ceased to feed our habit could appear to have run out of ideas.
On that, there is a solution. Most of the Gove education reforms and the IDS welfare reforms have still to be implemented. The same is true of Andrew Lansley's health measures – and of the public spending cuts. Over the next few months, all that will provide endless headlines, so it is most unlikely that the government will seem to be idling. New Bills: there is enough controversy in the existing ones to satisfy the most demanding radical's appetite – and that is before the manifestation of the unknown unknowns.