The electorate's unconcern about the private lives of politicians, however humiliating and absurd, is one of the psephological wonders of modern times. It's what got Piers Merchant comfortably re-elected at Beckenham on 1 May when the uxorious but financially flaky Neil Hamilton was bundled out at Tatton. It's what justifies and sustains the awesome fightback that Bill and Hillary Clinton are waging from the White House. And it's what makes almost all of what is being written about the British Foreign Secretary in the papers gunning for him, from The Mirror to the Daily Mail, irrelevant to his future. But the fuss still matters. For what is happening here is a rather interesting trial of strength between large elements of the press - and a Conservative Party riding on its back - and Tony Blair. Much of the press is having a high old time. It would be foolish to pretend that the row has done the Government no harm in either the party or the country. Yet it seems to be the Prime Minister who has the glint in his eye.

Cook can be a difficult and prickly man at the best of times; and these are not the best of times, given the personal pressures caused by the break-up of his marriage. Although his relations with most officials have been significantly better than portrayed, he harbours enmities. He has frustrated his own civil servants by showing marked reluctance to meet his nearest Cabinet neighbour, Clare Short. His long-standing association with Gordon Brown is distinctly icy; he isn't clubbable - scarcely, if ever, visiting the bars and tearooms of the Commons.

Cook, moreover, didn't help himself by saying that Anne Bullen, his departed diary secretary, was "impossible to work with". There was, by all accounts, a culture clash, with Miss Bullen, for example, scarcely able to believe that John Monks (general secretary of the TUC) might interrupt a meeting to speak to her new boss on the day that the GCHQ ban on unions was lifted. Cook might, more gallantly, have said: "Look, Miss Bullen is an extremely efficient woman. But we didn't see eye to eye. It may well have been my fault as much as hers. But a Foreign Secretary can't have a diary secretary who he doesn't get on with." But then humility has never been the Foreign Secretary's strongest suit. There was some irritation among those designated by the Labour Party with the day-to-day struggle to secure the most favourable headlines possible that he did not put himself more fully in their charge. Finally, he may not yet be as good as Clinton - the acknowledged past master - at focusing relentlessly on the political at the expense of the personal.

But there is also an element among some of his critics of establishment disdain for the Foreign Secretary, a disdain compounded rather than mitigated by his cleverness. Some on the diplomatic circuit would have preferred someone who had a long record of pro-Europeanism, such as the much smoother Jack Cunningham, or one who was plugged into the foreign policy network while in opposition, such as George Robertson. By contrast Robin Cook is the first Labour Foreign Secretary to come from the left of the party. The foreign policy establishment is more used to those Foreign Secretaries - from Ernie Bevin to David Owen - who routinely enraged the party's left wing. Some of this friction with the establishment is mutual: addressing the Parliamentary Labour Party on Wednesday, Cook remarked in passing on the fact that there were no British ambassadors of Asian origin, and that he had been struck that of 15 teenagers whom he had met doing work experience in the FCO only one was from a state school.

All of this no doubt has helped to make Cook a target; but it didn't, of course, remotely bear on his ability to do his job to the Prime Minister's complete satisfaction. True, his start wasn't perfect. The goal of an ethical foreign policy has proved, as some of his colleagues recognised at the time it would, a lot easier to announce than to deliver. (Though the idea that he was somehow disqualified from having an ethical foreign policy because of problems in his private life, peddled this week in the hostile press, is seriously laughable. Tell that to the people of East Timor.) The transition from opposition to office may have been more difficult for Cook than for some of his colleagues. In opposition he was a star, but what he mostly did was simply to oppose. He moderated, in opposition, his own hostility to EMU. But he did not, as Gordon Brown did, have to undertake the heavy - and far from internally popular - duty of transforming an economic strategy that had helped to cost the party three successive elections. But the handsome plaudits from Blair since the election for Cook's handling of his relations with his European counterparts, his management of the EU foreign affairs council last Monday, his unusually close working relationship with the US Secretary of State Madeleine Albright, his intellectual and political grasp of the brief, have all been genuine.

So Blair thinks Cook is doing an excellent job. Nor was there anything eccentric about wanting to replace a diary secretary with someone who had done the same job with manifest competence in opposition. Several other Cabinet ministers - Blair included - have done the same. He didn't appoint Ms Regan, in the end, because they were having an affair. He continues to deny that he was forced by the Civil Service to change his mind. Even if it had done so, the only thing about the episode that would baffle other European leaders was that he was too fastidious to overrule it. But none of this is really the point. Blair came into office determined not to do as Major did and let the press decide on who should and shouldn't be in his Cabinet. There may be a process of re-education going on here. British voters elect Foreign Secretaries to represent their interests abroad, not to be perfectly formed personalities in their private lives. Blair appears ready to have his doctrine of ignoring the trivially personal tested to destruction. If he stays the course, there could be long-lasting effects. Perhaps it's too optimistic to think so; but in the long run the fewer scalps that get taken, the fewer lynch parties there may be.