Defence analyst Ellie Goldsworthy, a former captain in the British Intelligence Corps now with the Royal United Services Institute, answers questions on some key elements of the Iraq conflict.
A fifth member of the British forces is reported to have died as a result of "friendly fire" - is this unusually high and why does it happen?
It is not an unusually high number, but there is still no room for complacency about "friendly fire" deaths.
There are basically two kinds. The ones which occur because of the "fog of war" and where troops are tired. You are unlikely to get rid of all these instances.
But there are some avoidable incidents of "friendly fire", such as helicopters crashing into one another.
The Ministry of Defence is instinctively defensive about this issue, but once the war is over I think it is important to hold a transparent and robust investigation of all the "friendly fire" incidents, especially those where they were obviously avoidable.
It appears on the ground that an operational "pause" is in place among the coalition forces in Iraq, although this is being denied by the US Central Command in Qatar. What are the benefits and costs of such a "pause"?
It allows for three essentials among forces - rest, re-supply and reorganisation.
It also gives troops an opportunity for longer sleeps, to wash and to maintain equipment.
But it can lead to a perception of a loss of momentum, which could possibly affect the morale of troops.
It can also give an opportunity for the enemy to regroup and plan counter attacks.
The posture can turn from offensive to defensive, with a location known to the enemy.
But overall, I would have full confidence in the military command on the ground to take decisions and I would rather see plans change to fit a situation, than see them crack on with a plan that is not working.
The Iraqi central command and control still appears to a large extent to be intact, how important is it to destroy it?
Until the central command and control is destroyed, the war will not be won.
The Iraqi forces are not sophisticated but they are resisting. It is their mood, morale and willpower that is worrying, but eroding the leadership can destroy that.
How could the coalition forces expect to win?
In previous conflicts - such as in the Falklands, Kosovo, the Gulf War and Afghanistan - there was always somewhere for the enemy to go. That is not the case here.
The enemy has nowhere to go and no option but to fight or surrender.
And they will not do that until it is safe to do so.