FOUR days ago, as President Bill Clinton was testifying to Kenneth Starr about his relationship with Monica Lewinsky, foreign diplomats in Pakistan were told that "all foreigners" in Afghanistan were in danger.

European embassy staff suspected that the United States, with the help of the Pakistani authorities, was about to assault Osama bin Laden, the Saudi dissident opposed to Washington's continued presence in Saudi Arabia. One foreign embassy official in Islamabad told me the sources were American.

Now we know why. But the results are likely to be incalculable.

President Clinton says that Mr Bin Laden declared war on the United States. Now Mr Clinton has declared war on him - which is exactly what Mr Bin Laden, guilty or otherwise of the American embassy bombings, will have wanted.

Mr Clinton wants to destroy Mr Bin Laden. Now Bin Laden will want to destroy Mr Clinton. He can count on the support of millions of Muslims who will never be persuaded that the strikes against Afghanistan and Sudan were anything but a cynical ploy to distract attention from Mr Clinton's sexual adventures. They are also aware that the camp in Khowst, in Paktia province, which the Americans bombed, was originally set up by the CIA to train Afghan - and Arab - guerrillas in their war against the Soviet army. For, in the 1980s, Mr Bin Laden and his men were regarded as "freedom fighters" rather than "terrorists" and were encouraged to use British-made Blowpipe anti-aircraft missiles against the Russians.

Mr Bin Laden demands the withdrawal of US troops from his native country of Saudi Arabia - some of whose officials give him considerable support. None of this, of course, was finding its way into the American news reports from Washington last night.

Of one thing we can be sure, that in the coming days the story will change. We will hear of civilian casualties. We will ask why Mr Bin Laden survived. We may even hear of secret deals - rumoured in the Middle East these past five days - between Tunisia, Libya, Egypt and the United States that would prepare the ground for the lifting of UN sanctions against Libya in return for its support in the war against Palestinian "terror": the story that Abu Nidal, the cruellest of Palestinian militants, has been secretly sent from Tripoli to Cairo in a semi-comatose state, persists.

Egypt, it is said in the Arab world, has demanded action against its domestic enemies - which may be why the United States helped extradite five Egyptians from Albania to Egypt and bombed Sudan.

And what was the Khowst base that Mr Clinton bombed in Afghanistan? When I saw Mr Bin Laden last year - ascetic, cautious, intelligent and very ruthless - we met at a moun-tain camp near Khowst. He possessed - a few metres from his tent - a massive air-raid shelter, cut into the rock of a mountainside, protection against anything bar nuclear attack and built during the height of his war against the Soviet army. Was this the "base" that Mr Clinton thinks he bombed?

Sudan was bombed, too. But was it not Sudan which, at America's request, ordered Mr Bin Laden out of Khartoum in 1996? Was it not Sudan which handed over Carlos the Jackal to French intelligence agents in August 1994? Was Sudan - a ramshackle dictatorship if ever there was one - really making precursor chemical weapons?

Meanwhile, the very word "terrorist" will incite the fury of Arabs. Yes, bombing embassies is an act of terrorism. But so is murdering Muslim worshippers in a Hebron mosque or assassinating an Israeli prime minister - carried out by Israelis but never called "terrorism". Double standards will be on the lips of every Arab this morning.

And if the word "terrorism" is now little more than racist terminology against Arabs, it also serves to silence the question "Why?" Last night not a single hint came from Washington as to why Mr Bin Laden - now taking the place of Abu Nidal, Colonel Gaddafi, Ayatollah Khomeini and Colonel Nasser in our book of hate - should loathe America. No suggestion that he wants US troops to leave Islam's holiest land.

No clue that he was obsessed - as he still is - with the Israeli massacre of 106 Lebanese civilians at the UN base at Qana in 1996, a slaughter (the Israelis said it was a mistake) for which he also blames the United States.

So President Clinton is declaring war on "terrorism", is he? If only he would, the Arabs will say today. And if only he would start by seizing the two leading "terrorists" in Europe's own backyard: General Ratko Mladic and Radovan Karadjic, responsible for the massacre of tens of thousands of Muslims.

But they are not the sort of "terrorist" Mr Clinton is looking for. Instead, he has decided to assault his enemies with their own weapons of violence. And Americans, as well as Arabs, are likely to pay the price.

Robert Fisk