By Jonathan Marcus BBC Defence Correspondent

More than a decade after its retreat from Kuwait and eventual defeat at the hands of a US-led coalition, Iraq's armed forces are at an even greater relative disadvantage compared with those of the United States.

Iraq's military strength

424,000 active troops 1,900 tanks 2,400 armoured personnel carriers 1,900 wheeled guns 300 combat aircraft Some short-range rocket systems Source: Independent US experts

On paper Iraq still retains what seems like an impressive military arsenal.

It has troops, equipment that may include a small number of Scud-type missiles, and a reasonably effective air-defence system that is used regularly against patrolling US and British warplanes.

But this is, in many ways, a wasting and increasingly obsolete arsenal.

Iraq has not been able to modernise its armed forces or to obtain sufficient spare parts to keep all its equipment in service.

So the ball-park figures have to be treated with caution.

Huge undertaking

Training for ground forces has continued, but Iraq's pilots have been greatly restricted in their flying due to the US-imposed northern and southern no-fly zones.

Tanks not destroyed during the Gulf War lack spare parts

Iraq's air defences, while quite capable of shooting down Western aircraft, probably do not have the regional, or certainly the national level of co-ordination that they had before the invasion of Kuwait.

Washington may yet look for other ways to destabilise Saddam's regime.

An invasion would be a huge military undertaking.

US forces would have to be gathered in the region and such a build-up would take time and require local support.

Unequal struggle

But if President George W Bush is determined to engage Iraq militarily, this would be an even more unequal struggle than when his father was in the White House.

Regular soldiers deserted in their thousands during Desert Storm

The war in Afghanistan has shown the extraordinary advances in terms of information-gathering systems and targeting available to the US military.

The morale of Iraqi forces must also be in question.

Some elements - like the armoured units of the Republican Guard might offer stiff resistance - but they would bear the brunt of the US effort.

Large portions of the Iraqi forces simply ran away or surrendered during Operation Desert Storm.

Chemical weapons

And American military pundits believe that next time around - if there is a next time - the Iraqis will have to contend with the military equivalent of a hurricane.

What is still unclear is whether Iraq has a significant chemical or biological weapons capability that it could deploy against an invading force.

Pentagon chiefs have to take such an eventuality into account in their planning.

President Saddam Hussein might regard such weapons as usable in a doomsday scenario should he be on the verge of being forced from office.

But such a step would not change the outcome of such a struggle and would, at a stroke, prove one of America's reasons for engaging Saddam's regime in the first place.