Comment: Good enemies need each other just as much as good friends do

Physical contact with a woman he loathed so cordially is taking years off Ted Heath's life

DOWNRIGHT SCARY, that picture of Lady Thatcher and Edward Heath. The photograph taken of them mustering one another at the 20th anniversary celebrations of her accession to power is a ghastly portrait of enmity masked as friendship. It reminds me of nothing so much as the caricature by Beaverbrook's cartoonist David Low marking the Nazi-Soviet pact. "Ah!" says Hitler, extending a hand to Stalin. "The bloody assassin of the people." "The scum of the earth, I presume," replies Stalin with a courteous bow. Between them is a map of a vanquished Poland.

Over the near-lifeless corpse of the Tory party, William Hague has set out to broker peace between the two warring Tory former leaders, a symbolic laying aside of the party's fratricidal tendencies. But the strain of the star-crossed enemies' first public appearance together during last year's party conference was palpable. To judge by this week's outing, they aren't getting any better at it.

She tries to manoeuvre his substantial bulk to one side with those gimlet eyes fixed warily on his face, apparently worried that he is about to take a swipe at her. The slightest physical contact with a woman he loathed so cordially is clearly taking years off the rest of Ted's life. Yet the ritual of reconciliation is played out doggedly. Both characters have decided that it now fits their personal screenplay to appear magnanimous in old age, even if the substance is lacking. It is enough to make you admire John Major, who discovered that he had pressing business somewhere, anywhere, abroad and wouldn't be able to make it to this parody of Tory Party unity.

The late 20th century inclines to celebrate understanding and friendship, even when we all know that the truth is darker. In the corporate culture through which Mr Hague rose as a young management consultant at McKinsey, the ability to get along (or be seen to get along) with all your colleagues equally is considered one of the most important implements in an executive's armoury.

A friend of mine from the former East Germany, who has just had his first exposure to the bonding session of a large company, was struck by the similarities of this enforced clubbability with morale-raising events for the young Communist movement before 1989. In both cases you don't in fact feel very much, but you give the impression of being moved and sustained by the company of your peers.

The political expression of this insistence on friendliness is the culture of consensus. Its rise has been a shared trait of the prosperous democracies. Europe is dominated by Social and Christian Democratic parties whose policies are practically indistinguishable to the naked eye. Mr Blair has blurred the divisions between left and right so effectively that it is hard for his opponents to appear other than extremist. Until the war in Kosovo, New Labour had rarely uttered a word in anger.

It still shakes us to hear Mr Blair being bellicose rather than emollient. He is now seeking to move politics beyond mucky confrontation and on to the sunlit uplands where all reasonable people can be expected to agree with him.

That is a paradox, since politics is the pursuit of power and the making of a choice, to which there will inevitably be alternatives. But the statement that consensus exists often pre-empts the emergence of the desired agreement. That is the dynamic of the Northern Ireland peace process - the longer it goes on, and the greater public support becomes, the harder it becomes to break it off.

Politicians have highly contingent views of friendship and enmity, a consequence of routinely using other people as means to ends. In my colleague Donald Macintyre's biography of Peter Mandelson, we read of Mr Blair's uncomprehending frustration at the rivalry between Gordon Brown and Mr Mandelson. "Have you any conception of how despairing it is for me when two people who have been closest to me for more than a decade... will not lay aside their personal animosity and help me win?" Mr Blair writes to Mr Mandelson.

What is extraordinary is not that two highly-strung and motivated men with competing claims on the leader's favour should vie for predominance but that Mr Blair, preoccupied with winning power, cannot really understand their unwillingness to subjugate their emotions to his needs.

Politics is the arena in which the categories of friend and foe mutate most freely - see that footnote in the Tories' tragedy, the short-lived leadership pact between the right-wing, Eurosceptic John Redwood and the leftish Europhile Ken Clarke. Yet however consensual they may pride themselves on having become, I suspect that the leading practitioners value their enemies rather more than they value their allies. Enmities define and sustain them in a way that friendships do not.

The Heath-Thatcher frisson is as intense as any relationship of comrades in a shared cause. They were the grit in each other's ideological oyster, the reason to continue the struggle. Even now, they represent the two camps in the Manichean battle for the Tory soul. Better just to admit it.

The allies of powerful people tend to be paler versions of themselves and thus incapable of providing the spur a really determined leader needs. So when Mr Blair faced his first European summit with Chancellor Kohl and President Chirac, he sought advice not only from his intimates but also from the great She-enemy herself about how to do business with these tricky foreigners.

The rest of us live in a culture where friendship is idealised, but it gets harder to find the real thing and keep it. We watch Friends by ourselves on a Friday night, or we flee our grumpy flatmates who are such a poor apology for the fond chumminess of Joey, Rachel and the gang. Thelma and Louise dominated the female imagination - but who would drive into the Grand Canyon with us if push came to shove?

New research investigating the way we do friendship concludes that the more affluent people are, the fewer close friends they are likely to have and the more likely these relationships are to be transient. In other words, we are not so different from those nasty politicos making their calculated alliances. "People are far more ruthless about abandoning friends if their faces no longer fit a current lifestyle," concludes the report.

Most of us have done it or had it done to us. The truly unfeeling don't even notice, but I suspect most of us do, more than we care to say.

Real, lasting friendship, the kind that evolves and survives knocks, is in shorter supply, pushed to the margins of our lives by shortage of time and the modern emphasis on sexual love. "My husband/ girlfriend is my best friend," we say proudly, wondering at the same time why our best friend isn't. It makes you grateful for your enemies. At least you can count on them.