Anthony Sampson: The war in Iraq is distracting the West from the looming crisis in Saudi Arabia

The ultimate nightmare for Western consumers is to find that the biggest oil exporter does not need to export

It is only when the British public have to pay more for their petrol at the pumps that they take much interest in where it comes from. And today, they are right to link the price of petrol to the war in Iraq. But motorists too readily vent their anger on the companies whose name they see on the signs, particularly the two British companies, BP and Shell, which have always been convenient scapegoats.

It is tempting to blame the oil companies for the shortage of oil, and to depict the war in Iraq as a straightforward attempt to control its oil reserves in the interests of the big corporations. But the remarkable fact is that Tony Blair, though he talked much about British interests, prepared for war without consulting the companies that had the greatest interests in, and experts on, Middle East oil. And, in fact, both Sir Philip Watts of Shell and Lord Browne of BP were warning that war in Iraq was likely to destabilise supplies and antagonise other Islamic oil-producers.

It might seem surprising, but it has happened before. When Sir Anthony Eden launched the Suez War in 1956, also claiming to defend British interests, he did not consult Shell or BP, which had the most to lose. Both companies were deeply worried that such a dangerous adventure would antagonise Arab oil-producers through the Middle East - which it did, damaging British relations for years to come.

The truth is that governments that are bent on military adventures - contrary to most conspiracy theories - become curiously resistant to advice from commercial concerns, which often understand much more about the consequences. Before the Iraq war, the neo-conservatives in Washington had their own view of the importance of oil: they saw Saddam Hussein as a huge obstacle to American power, who was sitting "on top of 10 per cent of the world's oil supplies", as the Vice-President Dick Cheney explained.

They saw Iraq as a "huge gas-station", which could be liberated to reduce American dependence on the other gas-station, Saudi Arabia. And they wanted to break the power of Opec, the Arab-dominated oil cartel, and ensure cheap oil for American consumers. But they wanted to go to war with Iraq primarily for quite other reasons - to revenge the humiliation of 11 September, and to assert American influence and military supremacy in the Middle East. And their policy amounted to a reversal of the oil companies' policies over the previous decades, which had depended on co-operating with Islamic countries - which had most of the world's oil supplies under their ground.

It is important to look back on this fundamental reversal, which may prove to be the most serious blunder behind the war. For a continuing high oil price could do more economic damage to the West than any terrorism so far.

In the post-war decades, oil had been the most potent element in creating nationalism in Islamic countries. The awareness that Western companies were exploiting their oil-wealth provoked the successive popular revolutions against pro-Western regimes, including Iran in 1951 and Iraq in 1958, and the formation of Opec in 1960; and the nationalist regimes gradually compelled firms to share their profits and control. It was the growth of Arab nationalism, together with anger against Israel, that finally enabled the oil powers to create their own cartel in 1973, which quadrupled the oil price and set back Western economic growth for several years.

The Western countries reduced their dependence on Opec by the Eighties, as they discovered more oil outside the Middle East, while Opec realised they had a common interest in securing stable prices and markets. But as oil became cheaper, Americans became more extravagant, while new industrialised countries, led by China, became huge new consumers of oil.

The key to supplies remained Saudi Arabia, the most important source of oil for the West, but it became more problematic. The US companies were determined to maintain good relations with the Saudi monarchy at all costs. But their corruption and ridiculous extravagance were provoking more discontent among the growing Saudi unemployed, who were turning towards fundamentalism; while many Saudi princes were buying them off by financing radical mosques and political movements.

It was Saudi wealth and corruption that provided the original provocation for Osama bin Laden and his teams of terrorists, first in Afghanistan and then across the world, while they became more determined to overthrow the corrupt monarchy inside the kingdom. Bin Laden made no secret that his eventual ambition was to seize power in his home country, and to re-establish the austere Wahabi religion on which the country was founded. But the Iraq war provided a massive distraction - as many had warned - from this ultimate nightmare.

The US neo-conservatives saw the liberation of Iraq as the means to counter their dependence on the Saudis, as Iraq's huge newly-found reserves could soon be brought on to the market. But the war has so far had precisely the opposite effect: Iraqi resistance has seriously limited oil production.

At the same time, the security of Saudi Arabia has looked much more doubtful. The Saudi government, with much US help, has massively increased the military defences of its own oilfields, with an estimated 20,000 troops and security guards. But the Americans have also become much more critical of the Saudi monarchy, while they are confronting internal terrorists who threaten to undermine their whole control.

The extent of the revolt is hard to assess, for foreign journalists now have great difficulty in entering the country. But the well-informed newsletter Energy Intelligence gives a worrying account of the insecurity inside the kingdom. After terrorists attacked the security headquarters, the government declared an all-out war against the extremists, but new militant groups keep appearing. And in the end, there can be no purely military solution against an internal enemy.

The war in Iraq, with all its blunders and horrors, has continued to distract the West from the crisis in Saudi Arabia, which was the more serious consequence of 11 September, and the ambitions of Osama bin Laden. A civil war in Saudi Arabia could provide a greater threat to Western security than either Iraq or Afghanistan.

For if the fundamentalists were eventually to take control of Saudi Arabia, they would not feel the same necessity as other producers to sell their oil to finance their development. They believe that it is wealth that has corrupted their country, and they could manage without it. That is the ultimate nightmare for Western consumers: to find that the biggest oil exporter does not need to export.

It is the growing uncertainty about the future of Arab oil supplies that lies behind the mounting price of petrol at the pumps. And as motorists complain about the cost of their journeys, they should question their government, not the oil companies. How they could have embarked with so little consultation on a war that would provoke such instability in countries on which they desperately depend for their oil?