Anthony Sampson: It's the spooks, not the diplomats, who are in charge of foreign policy now

Who is now making British foreign policy, and who should be? These are questions which have to be asked urgently, particularly after reading the Hutton and Butler reports.

Who is now making British foreign policy, and who should be? These are questions which have to be asked urgently, particularly after reading the Hutton and Butler reports.

It is clear that we have been facing a totally different world since September 2001, and still more since the Iraq war. But it is not clear that we have carefully re-thought who are our enemies, who are our friends, and how best to deal with them. And it is still less clear after last week's announcement of defence cuts, which gave no picture of what the armed forces were for - except as adjuncts to the Pentagon.

So who is actually deciding about Britain's role in the world, besides the Prime Minister? It is important to retrace how Iraq has served to re-shape the pattern of policy-making.

It was apparent in the run-up to the Iraq war that the Foreign Office had become less important. The head of the service, Sir Michael Jay, appeared largely out of the loop, while much of the serious diplomacy was conducted by Tony Blair's personal adviser, Sir David Manning - now ambassador in Washington.

The British ambassador to the UN, Sir Jeremy Greenstock, was crucially important in seeking diplomatic support for the war, and in eventually blaming the French for withholding it; but he was clearly following the Prime Minister's instructions, and could never deviate far from the American line. Later, as Britain's special representative in Baghdad, he appeared deeply frustrated by the domination of the American proconsul Paul Bremer - and thankful to retire from the service.

The foreign service had little opportunity to put forward a separate policy from the Americans', or Blair's. Most of the ambassadors in the Middle East, with all their expertise on Arab politics, felt excluded from the crucial discussions - an exclusion which was reflected by the notorious letter of protest written to Tony Blair by the 50 retired diplomats, mostly Middle East experts.

And the scope of British diplomats to influence the Americans was further weakened by the shift of power in Washington, where the Secretary of State, Colin Powell, had lost out to the National Security Adviser Condoleezza Rice, and to the Pentagon under Donald Rumsfeld. The Pentagon, rather than the State Department, had become the dominating influence of foreign policy, with its own diplomatic service round the world.

In London, the British military experts in the Ministry of Defence had no corresponding increase in influence. Many generals and senior defence officials were known to have serious concerns, both about the preparations for war, and about the post-war American policy in Iraq; but Geoff Hoon had far less political clout in No 10 than Rumsfeld in the White House; and his ministry, anyway, had little scope to moderate American policies in Baghdad. As the war situation in Iraq continued, military solutions had priority over diplomatic ones.

In the meantime, the intelligence services had become more important than diplomats since 11 September 2001, and their role before the Iraq war - as we now know in remarkable detail - was crucial in providing its justification. For it was an "intelligence-led" war, a pre-emptive strike which could only be legitimised through convincing intelligence.

The intelligence services had already gained much importance in all major countries since 11 September, which put much more emphasis on terrorism above all other dangers to the state. Tony Blair had preferred listening to the intelligence chiefs, whose evidence impressed him, than to diplomats. Now he felt much more need for their support.

The British Government's relations with other countries were coming to depend more on the international intelligence community, which was closer-knit than the conventional diplomats. And the Government was dealing with allies in the developing world whose intelligence chiefs held the keys to decisions at the top.

Governments in countries such as Pakistan, Egypt or Israel gave more priority to security than diplomacy. Their presidents and prime ministers were less interested in the views of ambassadors than in the station chiefs of the CIA or MI6. And the intelligence headquarters in Europe and Washington were increasingly rivalling the foreign ministries as the centres of global diplomacy.

Of course, their information included a great deal of disinformation. Both the CIA and MI6 have rightly taken a battering over the last few weeks, as their failures have been revealed - whether to foresee 11 September, or to interpret the real situation in Iraq. And they have lost more of the public's trust.

But whatever their shortcomings, they will inevitably increase their influence over the coming years. Not only because they will be seen as the experts on terrorism, which will continue to be the preoccupation of governments; but because they are having to learn much more about the social, cultural, and religious forces underlying terrorism.

This may well prove their most difficult challenge, but also their great opportunity to compete with Washington. The Americans have always been weaker in linguists and Arabists who really understood the people with whom they worked. And the first American response to 11 September was to view with suspicion anyone who was too close to Arabs or Islam.

The British, in their imperial past, prided themselves on their experts on remote languages and cultures in the Middle East or Central Asia, including eccentric scholars or explorers who established close links with remote tribes. Such expertise became much rarer in the post-imperial era, as human intelligence ("humint") gave way to signals intelligence ("sigint").

But the British still have a tradition of Arabists and Middle Eastern experts; and as the mistakes of Iraq have sunk in, it has become more obviously essential to understand the "hearts and minds" in the Islamic world; to be tough on terrorism, but also the causes of terrorism. Now MI6 is trying rapidly to recover that earlier expertise, by recruiting and training more specialists and linguists - though they will take some years to show results.

This wider scope, with bigger budgets to finance it, will inevitably make the intelligence services still more important within the British Government, whatever their past mistakes. But that raises more urgently the question of how they are supervised and controlled. For Parliament cannot tolerate such a powerful fiefdom growing further with the lack of oversight that both Lord Hutton and Lord Butler have revealed.

Tony Blair's appointment of John Scarlett to run MI6, after the severe criticisms of his role in the Joint Intelligence Committee, has rightly brought the issue to a head; particularly since his empire will become much wider. We may have to accept that the secret service will loom larger in making British foreign policy, but we have to be reassured that it is run by a person we can trust in the job.