Roosevelt gained direct experience of wielding the big stick as a commander of the Rough Riders Regiment in the 1898 Spanish-American war, the first instance in which the US deployed military force to achieve regime change in other countries. The war was a logical extension of the Monroe Doctrine, which effectively entailed declaring the Americas as an exclusively US sphere of influence. The one that the US administration is now threatening to unleash on the Middle East appears to be based on a global expansion of the scope of that original American presidential doctrine.

The American perception of the Middle East as a US sphere of influence is not exactly new. What has changed is that the US is now apparently considering the occupation of a large Arab country, and the active involvement in running its affairs for a number of years in order to safeguard that sphere of influence.

The modern era of US engagement in the Middle East started in 1945 with the historic meeting between King Abdulaziz of Saudi Arabia and President Franklin Delano Roosevelt. The Saudi ruler correctly perceived the advantages of working closely with the rising global power, and the meeting laid the basis for a strong relationship that has survived to this day - although there are now serious questions about how much longer it can last.

The next milestone for US policy in the region was the 1956 Suez crisis, when President Eisenhower managed to secure a withdrawal of British, French and Israeli forces from Egypt through threatening to impose economic sanctions on the UK.

This was the last occasion on which the US forced Israel to withdraw from Arab territory. Over the succeeding decades, US policy became more and more beholden to Israel. In 1967, the Johnson administration acquiesced in Israel's dramatic victory over the Arabs, and in the 1973 war, a massive US airlift of weapons ensured that Israel held the upper hand when hostilities ceased. However, the oil embargo of that year rammed home to the US the potential for conflict between the interest of backing Israel and that of safeguarding cheap energy supplies to the West.

The US sought to resolve this problem by building up the Shah of Iran as a kind of pro-Western regional policeman, who could act both as a buffer between the Soviet Union and the Gulf and as a force to keep the Arab oil states in check. That policy came dramatically unstuck with the Iranian revolution of 1979, and the US then concluded that there was no alternative to having a direct military presence in the region.

There was resistance to having permanently manned US bases in Arab countries, and so the US came up with the idea of a rapid deployment force that would be able to make use of base facilities in the region in emergencies. When Iraq invaded Kuwait in 1990, it became clear that the US could deploy forces in the region, but only after lengthy political and logistical groundwork had been completed.

Once Iraqi forces had been ejected from Kuwait, the US made an effort to tackle the Arab-Israeli problem. For the first time, Washington recognised that the PLO would have to be involved in this process, and that Palestinian statehood was a possible outcome. As for Iraq, the Bush (senior) administration had made the fateful decision to conclude an early ceasefire with the Saddam Hussein regime, and had made no move to support the uprisings in the south and the north of the country. Dual containment of Iraq and Iran was what the Clinton administration chose to call a policy that amounted to preservation of the status quo.

When George W Bush administration took over at the start of 2001, it quickly became clear that he would seek to keep the Middle East at arms length. Bush resisted the clamouring of Arab leaders for Washington to play a more active role in dealing with the Palestinian crisis, and his deputy, Dick Cheney, produced an energy policy review which was remarkable for virtually ignoring the Middle East, while highlighting the need to develop new upstream sources of oil and gas.

It was also evident early on that there were some important differences of emphasis on foreign policy within the administration. Secretary of State Colin Powell represented one extreme, with a commitment to active international diplomacy. At the other was deputy defence secretary Paul Wolfowitz making the case for military action to overthrow Saddam Hussein.

Powell has never looked entirely comfortable in the administration. He had a brief spell of prominence after the 11 September attacks on New York and Washington, when he played a vital role in mobilising international support for US military action against Afghanistan. However, once the military action started, Powell faded into the background, as Defence Secretary Donald Rumsfeld took centre stage. Powell's lowest point came in April this year when Bush dispatched him to the Middle East with instructions to secure an Israeli withdrawal from reoccupied Palestinian territory. He made no headway during his 10-day visit, and exited the region with the convoluted statement: 'The specific term ceasefire has not quite the same significance as what actually happens as opposed to a specific term.'

Crown Prince Abdullah of Saudi Arabia, during his visit to the US at the end of April, pressed the case for Bush to take a more resolute stand against Israeli Prime Minister Ariel Sharon. However, when Bush stood up on 24 June to deliver his final word on the issue, he laid the emphasis on the need for Palestinian political reforms. Bush's call for a change of Palestinian leadership reflected the views of the hardliners in the administration - led by Rumsfeld and Cheney - and was subsequently reinforced by National Security Adviser Condoleezza Rice.

However, the US administration has not completely discarded Arab demands for greater engagement in the search for a solution to the Palestinian problem. Powell and Rice met Palestinian officials in Washington in mid August to discuss plans for political reform, and the US has reacted positively to the efforts of two newly appointed Palestinian ministers - Abdel-Razaq al-Yehiya and Salam Fayyad - to deal, respectively, with security and finance. The Bush administration has also stated explicitly that it sees the creation of a Palestinian state as an essential element in any regional political solution.

Arab leaders have sought to persuade Bush to keep the Palestinian issue at the top of the administration's Middle East agenda. The most recent such call came from King Abdullah of Jordan. 'Trying to even take on the question of Iraq with the lack of positive movement on the Israeli-Palestinian track seems at this point rather ludicrous,' he said on 29 July in Washington before meeting Bush.

These pleas and the reservations voiced by senior congressmen and former officials have had little discernible effect on the Bush administration's resolve to press forward with its campaign to unseat Saddam Hussein. Bush continues to state that all means to this end are being considered - diplomatic and financial as well as military - and that no final decision has been taken. However, there are growing signs that active preparations are already being made for war on Iraq.

The US maintains that the terms of UN Security Council resolution 687, enshrining the 1991 ceasefire, entitle it to use military force to neutralise the threat of Iraq's development of weapons of mass destruction. US officials have also indicated that they are confident that a new Iraqi regime, based on a democratic coalition of exiled opposition groups, can be installed once the Saddam Hussein regime has been removed.

The Bush administration could still be stopped in its tracks if Baghdad were to climb down on the issue of the unconditional readmission of UN weapons inspectors. The Iraqi leader's previous behaviour in the face of such situations suggests that this is unlikely. Another possible spanner in the works could be Congress. Bush will have to make some careful calculations on how he handles the Iraq issue in light of the mid-term elections in November. A quick war completed with minimal US losses before the elections would clearly be a boost for Bush's Republican Party, but it is not clear whether there is sufficient time for such a campaign to be executed. Another option would be to leave the operation until the start of 2003, with a view to cashing the dividends of a successful war and an economic recovery during the 2004 presidential election campaign.

Bush has also to take into account the climate of international opinion, which is strongly against the idea of the US waging war on Iraq in the absence of a fresh UN resolution authorising such action. If Bush does decide to go ahead, he will be seeking to win the support of UK Prime Minister Tony Blair. However, the British leader faces formidable domestic opposition on this issue, and may be inclined to urge caution on the US.

Another pertinent question for Bush as he weighs his options is the future of Washington's relations with friendly Arab states. There are worrying signs that the intimate relationship between the US and Saudi Arabia, nurtured by both sides since the discovery of oil in the kingdom in the 1930s, is starting to unravel.

The involvement of Saudi nationals in the 11 September attacks has made a deep impression on US views of the kingdom. The extent of anti-Saudi opinions in some quarters was brutally exposed in the mid-July Defence Department policy briefing that was leaked to the press on 6 August. This was followed one week later by the announcement of a multi-trillion-dollar suit against Saudi businesses and top officials in relation to the 11 September attacks (see Cover Story).

Despite the official protestations from both sides that US-Saudi relations remained strongly rooted, it is evident that the relationship has been damaged. Saudi Arabia has made clear that it will not allow its territory to be used for an attack on Iraq. If that veto was extended to Saudi airspace, US operations could be severely impacted. There is also the question of Saudi government investments in US securities. A withdrawal of these funds would only add to the woes of the US economy. Finally, the US has in the past been able to count on Saudi Arabia to supply extra oil to the market in times of crisis. If Riyadh felt that there were elements in the US administration intent on destabilising the kingdom, it is questionable whether Riyadh would be so obliging with its oil supplies this time around.

Aside from all these considerations, Bush has to make critical judgements about the feasibility of achieving a speedy overthrow of the Iraq regime and about installing a successor regime with sufficient power to allow a relatively prompt exit of US forces. The danger is that the US could find itself involved in a prolonged, ultimately unwinnable conflict along the lines of Vietnam.

There are also some parallels that can be drawn with the period of Theodore Roosevelt. The first time US forces were deployed far from home to consolidate a sphere of influence was in the Philippines in the Spanish-American war. The early victories of the US forces in 1898 were followed by a three-year rebellion, put down with extreme brutality. The great American author Mark Twain observed: 'We have pacified some thousands of the islanders and buried them; destroyed their fields; burned their villages, and turned their widows and orphans out-of-doors; furnished heartbreak by exile to some dozens of disagreeable patriots; subjugated the remaining 10 million by Benevolent Assimilation, which is the pious new name of the musket; we have acquired property in the three hundred concubines and other slaves of our business partner, the Sultan of Sulu, and hoisted our protecting flag over that swag.

'And so, by these Providences of God - and the phrase is the government's, not mine - we are a World Power.'*

There is no doubt now about the US' status as the World Power. Whether it needs to prove it by the direct exercise of military force to engineer a change of regime in Iraq is another question altogether.

* Quoted in A People's History of the United States, Howard Zinn, HarperTrade, New York, 1980.