By Tom Carver BBC Washington correspondent

Beyond the talk of Saddam Hussein and weapons inspectors, there is another factor at play in the White House war plans - ideology.

Some of the president's most senior advisors believe that the overthrow of Saddam Hussein is just the first stage in a long-term vision of change for the Middle East.

Installing a democracy in Iraq, even an imperfect version of it, would send shock waves through the region, the hawks argue.

They believe that Syria, Saudi Arabia and Egypt would be put on the spot and forced to become more democratic.

The Saudis have lost influence in the US

"There's not a single democracy in the 22 nations of the Arab League," a senior administration official recently observed. "Why should that be the case?"

Democracy would reduce the frustration of ordinary Arabs, reduce their appetite for radical Islam, improve relations with the United States and add a new element to the Israeli-Palestinian issue.

The intellectual underpinning of this vision comes from Paul Wolfowitz, a former academic who is now deputy secretary of defence.

But these views are also shared by his boss, Defence Secretary Donald Rumsfeld, as well as the vice-president and the president.

Regional change

None of them accepts the conventional wisdom that the Middle East is insoluble.

They believe they can change it for the better, starting with Iraq.

From there, the argument goes, other benefits will flow.

Once Saddam has gone, there would be less requirement for American troops in Saudi Arabia.

That would remove another major source of anti-Americanism, and undercut support for al-Qaeda.

Since America is the one expending military capital in liberating Iraq, you can be sure American companies would be given the best contracts in the reconstruction and access to Iraq's oil.

Saudi displeasure

This would reduce America's reliance on Saudi Arabia even further.

In fact, this administration has no qualms about upsetting the Saudis.

To the fury of the Saudi royal family, Saudi visitors to America are now routinely fingerprinted and searched.

They have lost the special status they enjoyed under the presidency of George Bush senior.

There's not a single democracy in the 22 nations of the Arab League...why should that be the case?

Senior US official

The hawks argue that America can use its military power as a force for good by exporting its founding principles of "liberty and justice for all" around the world.

American foreign policy should be 'forward leaning', not shy about interceding - some would say interfering - in conflicts.

All this the hawks have believed for some time.

But before 11 September, their ideas never got beyond theoretical policy papers.

The attacks gave them the opportunity they needed to test out their ideologies in practice.

Buoyed by the relatively painless experience in Afghanistan, they are now ready for Iraq.