By Nick Childs BBC Pentagon Correspondent

American officials continue to insist that no decisions have been made, but President Bush now has on his desk a detailed set of military options for an attack on Iraq.

American military technology has moved on greatly in the more than 10 years since the Gulf War.

And US military commanders believe that advances in surveillance, targeting, and communications over the last decade, and new weapons like pilotless aircraft, mean that any new showdown with Baghdad would be no simple rerun of the last Gulf War.

An arms show at a US Marine Corps base outside Washington last week was a showcase for some of the most advanced technology now available to the Pentagon.

Remote-controlled robots could detect nuclear or other hazards

Brigadier General John Paxton of the US Marine Corps certainly believes that today's marine is much more effective than his predecessor of a decade ago.

"He can move further ashore. He can bring more rounds to bear. His communications capability, his target acquisition capability, his manoeuvrability are all enhanced," he said.

All these make the marine of today a much better fighter, he said.

The military machinery has also come a long way since the Gulf War.

A tiny robot was demonstrated at the arms show. Fitted with tracks, the robot is barely bigger than the average radio-controlled car.

Cave searches

The marines believe it could be one of their most valuable allies.

It was used in Afghanistan to help search caves and bunkers.

You would rather have the robot stick its head around the corner rather than have your soldiers stick their heads around the corner

Grinnell More Research Director iRobot

Grinnell More, who works for the company which makes the robot, says it could find a role in Iraq.

The small size makes it easily and rapidly deployable. It can be carried by a single soldier.

"It can support different kinds of payloads that could sense radiation or a biological hazard or a chemical weapon and feed that information back to a soldier at a remote location," he said.

Some have expressed concern that if the goal of the United States is regime change, fighting might evolve into bloody house-to-house combat with high casualties.

In that case, the robot could be sent into a building first for reconnaissance.

Recent war games show how low-tech tactics could frustrate high technology

"You would rather have the robot stick its head around the corner rather than have your soldiers stick their heads around the corner," he said. "It simply reduces the hazards of the mission."

But some US marines found in a major exercise last month that their new equipment and tactics didn't provide all the answers when it came to urban warfare.

The exercise showed that they could suffer heavy casualties.

Lieutenant General Paul Van Riper played the enemy in that exercise, and created havoc for the high-tech American forces by employing some low-tech tactics.

He is worried that too much reliance on technology risks repeating the mistakes of the Vietnam War.

Smart bombs

Air power and precision, or so-called smart bombs, will also play a much greater role in a new conflict with Iraq.

Most scenarios for a new Gulf War suggest it will open with a much more devastating air campaign than last time.

More than a decade ago in Iraq, fewer than 10% of the weapons used were precision munitions.

In Afghanistan, it was more than 50%. In Iraq next time, the percentage would be higher still.

The technology gap between the American and Iraqi forces has certainly grown in the last decade. But the stakes are higher this time, and maybe the uncertainties too.