With the advance stalled 50 miles south of Baghdad, the view grew that the Pentagon's determination to make a rapid surge towards the capital with minimal troops had left a supply line that was too long, poorly protected, and open to attack.

Up to 50,000 troops and 7,000 vehicles are stretched along the highway from Kuwait to Kerbala, where the advance guard, the 20,000-strong 3rd Infantry Division, has been waiting since Monday. The 3rd alone consumes 600,000 to 750,000 gallons of fuel every day.

The 1st Marine Division, held up around Nassiriya and Najaf by the most severe fighting so far, as well as brigades from the 82nd and 101st Airborne Divisions, are also low on food, fuel, water, and ammunition.

Brig Gen Vince Brooks, a senior planner at US central command in Qatar, accepted yesterday that the severe sandstorms midweek had delayed supply logistics. He would not accept that supply lines were overstretched, but there is a growing fear that logistics has become the battle plan's biggest weakness.

Iraqi forces are attacking at every opportunity, from Basra in the south up to Kerbala. These attacks are especially fierce where supply lines pass by towns and cities, some of which are large and difficult to clear of enemy forces.

The Euphrates road crosses a wide river valley with many small villages set in marshland and irrigatedfields. Even 100 miles inland, it is still only 60 feet above sea level, making it ideal for guerrilla warfare.

Around Nassiriya on the Euphrates, US forces are fighting violent battles to establish a supply line for a new axis of attack by marines towards Kut. If they succeed in pressing deep into the marshland, they will have to pass through the city of Diwaniya with a population of 400,000. Beyond lies hundreds of miles of marshland before Baghdad.

Defence analysts said that US defence secretary Donald Rumsfeld's search for a new form of warfare led him to ignore two fundamental tenets of strategy when advancing into the attack: do not let your forces be attacked from the side, and do not let your supply lines come under attack.

Charles Heyman, editor of Jane's World Armies, said: "There is no effective force protection on the supply line at all, and it is far too long. First, they have had to contend with all the problems you would get moving their supplies over that kind of distance even in peacetime, like vehicles breaking down and bad weather.

"On top of that, they are facing partisan warfare - and that is now a serious problem."

There is also the delay in securing Umm Qasr. It was not until yesterday that the port was open. Even when military supplies do land, they would have to go by truck across more than 200 miles of hostile territory to the frontline.

For the push so far, the supply lines start more than 350 miles south of Kerbala at the American base at Arifjan south of Kuwait City, the operations centre of 377th Theatre Support Command, the unit co-ordinating logistics.

The heart of the Arifjan operation is a computer system modelled on that used by Federal Express. Each item going through the base, from a box of boots to a Bradley fighting vehicle, is bar-coded and tracked by computer. The system also monitors how much fuel, ammunition, and water each frontline unit is consuming, and organises resupply runs.

Chains of drivers take fleets of 5,000-gallon tanker lorries all the way from Arifjan to the advance forces. Each driver covers a stage of 200 miles - 14 hours' driving - before swapping the trailer onto another tractor that continues north, while the first driver returns to start all over again.

The US is trying in two ways to resolve the problem. The first is to refurbish several Iraqi airbases along the route, including one at Talil near Kerbala, so it can fly in supplies. However, many planes will have to arrive long haul from Europe, or the US itself, as the only other airfields, in Kuwait and Qatar, are overstretched in supporting bombing raids.

The second is to bring in from the US 100,000 troops as reinforcements to protect supply lines - but these forces bring with them another huge supply requirement. And as they try to clear the river road of resistance, they will be drawn into battles deeper and deeper in the marshland.


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