As I drive around the city, I do not get any sense of enormous defensive positions, tanks out in the streets, or huge military encampments.

There are no checkpoints and no curfews. Baghdad is still an open city.

However, there might be large numbers of forces secreted away within the city.

Certainly the Iraqi authorities are exuding an enormous amount of selfconfidence.

A few days ago, I asked the Iraqi minister of defence which Republican Guard positions were being hit and how badly, but he did not reveal much.

What he did say was that the Iraqis had learned lessons in the first Gulf War.

They were not going to leave their troops massed in their thousands, waiting to be picked off by Apache helicopters like sitting ducks.

The minister of defence also said they had taken measures to have their divisions broken up into small units that could be deeply dug into the city in the event of urban warfare.

Now, as a British journalist, I'm not going to be allowed to visit Iraqi forces and take pictures of them to verify what he says.

But to a certain extent I believe him.

The Iraqis have had a year to prepare for this war. They know how their whole military collapsed in Kuwait the first time, and they will not let that happen again.

So it could be that what the B-52s are doing on the outskirts of Baghdad is simply pounding empty sand and

empty buildings. I do not know.

What I do know is that we have seen evidence of small units of 10 to 15 men scattered throughout the city.

It is clear that the defence of Baghdad goes down to the very basic unit of the neighbourhood. It is not one large army defending a whole city.

The local officials who lead the units - be they from the ruling Ba'ath party or from the army - know their neighbourhoods extremely well.

This is one of the advantages the Iraqis will have if it comes to house to house fighting.

The US and Britain have not had diplomats on the ground in Baghdad for 12 years now, so their intelligence may be out of date.

However, there will be disadvantages for the Iraqis regarding urban warfare.

They have technologically inferior weapons, and they are open to surveillance from the air. If water, electricity and supply routes are cut off - if it turns into a classic siege - it will be very difficult for the Iraqi military, as well as for the Iraqi people.

It is hard to tell what the citizens of Baghdad really think of the war because this is a very controlled society. From what I have seen though, I think that people are genuinely afraid of the consequences of a siege of Baghdad.

There are likely to be more civilian casualties, particularly if the coalition forces try to minimise their own losses by continuing bombardments. What is certain is that the longer the war goes on, the more the people of Iraq are being affected.