Radical Shia cleric Moqtada al-Sadr and his Mehdi Army have given the Americans and the interim Iraqi government a specific target to fight and crush.

So far, attacks mounted on the occupation forces in Iraq have come from disparate dissident quarters - believed to be remnants of the Baathist regime or Iraqi nationalists.

Both the terms are too broad for the occupation forces to decipher and arrive at a specific group or militias whom they can set about chasing and eliminating. Moqtada Sadr's Mehdi Army has thus put names and faces to the 'enemy' in Iraq that had hitherto remained elusive for the occupation forces.

The latter are now going all out to crush this identified group of dissidents, there by making a horrible example of it for the rest of the elements fighting occupation. But in doing so the occupation forces and the interim Iraqi government are overlooking the fact that a rout of the Mehdi Army cannot be made an example for others.

The facts on the ground vouch for this: the bulk of the resistance put up by the Iraqis is coming from the Sunni triangle in the central part of the country stretching between Baghdad and Mosul.

Military action in Fallujah has failed time and again to root out such resistance. The same has been the case in areas around Mosul where nationalist militias are scattered, often leaderless and without a central command and control structure.

These dissidents will continue to strike at the very roots of the interim government which they see as nothing more than a stooge of the occupation forces. How the disparate militias acquire firearms is anyone's guess.

In a country where every adult Iraqi was conscripted by force and trained as a soldier by the former Baathist regime, there should be no dearth of firearms. In fact guns and ammunition formed an integral part of an individual's personal possession.

When the Saddam regime fell and the million-strong Iraqi army disappeared overnight, the huge stockpiles of ammunition in Iraq's ordnance depots was left unsecured. The looting of the arms depots started in the immediate aftermath of Saddam's fall. By the time the occupation forces got to these, they were found almost empty.

It is not as if someone managed to move those hundreds of thousands of firearms somewhere safe; a large number of Iraqis, including teenagers, picked up as many guns and as much ammunition as they could. No serious effort has since been made, either by the former interim administration or the current one, to undertake a disarmament drive.

All the same, the stakes, with regard to cleaning up the Mehdi Army, are immeasurably high for the Americans and the interim Iraqi government. Although Moqtada Sadr does not have a power base in the southern Shia heartland, his militiamen have been able to take control of the holy cities and Shia shrines across Iraq.

The grand-seminary, the Hauza at Najaf, and those running the religious establishment in the south of the country may despise him for his unbridled ambitions and a radical version of Islam, but there will be enough among the disgruntled and jobless youth whom his activist brand of Shi'ism will attract.

Founded in June last year, the Mehdi Army has managed to recruit up to 10,000 young men - all volunteers, below the age of 25. The spread of his activist religious ideology, demanding a greater role for Iraq's majority Shias in the future political dispensation, has so far found many takers, especially in the economically depressed south.

The heavy fighting reported with Moqtada Sadr's sympathizers in the southern city of Kut, situated a good hundred miles west of Najaf and the hostage taking of a British journalist in Basra are pointers in that direction.

Prime Minister Iyad Allawi's interim government is well aware of these realities. That is why attempts are being made to negotiate a political settlement with Mr Sadr's supporters.

An apparent truce seems to have taken effect since last night as a result of which the kidnapped British journalist has been set free, but a formal announcement has yet to come from Baghdad.

The terms now being offered are reasonably fair: that militiamen vacate the holy cities and become part of the mainstream political process. But many of Mr Sadr's opponents believe that this goes against the very grain of his ideology: power is not to be shared, it is to be wrested away as a matter of right.

The choice of Najaf as the battleground also has to be taken into account. It is the theological capital of Shias everywhere, so its symbolic significance cannot be ignored.

Condemnation of the military action underway in Najaf has come from Shia scholars around the world - from Tehran to Beirut to London. The unspecified but believed to be a high number of casualties there have led many to call the city a second Karbala for Shias.

From the Mehdi militia's point of view, Najaf also has a strategic importance unmatched by any other Iraqi city. The cemetery there is spread over an area three times the size of the city itself and can well be described as the Tora Bora caves of Iraq.

The population of Najaf is 700,000, while the cemetery dating back to the seventh century and stretching as far as 10 miles beyond the city is home to an estimated five million graves and tombs, many of them with underground burial chambers.

The thousands of narrow alleys going zig-zag among tombstones make a search operation a difficult proposition. These can provide an excellent refuge to a militia willing to fight to the death.

The Iraqi government and the Americans, however, cannot afford to prolong the fight, especially in and around the holy city. Doing so would risk radicalizing the Shia majority, which has largely remained calm so far.

No one is more acutely aware of this than Mr Allawi, but his dubious credentials matching those of Saddam Hussein's erstwhile lieutenants have preceded his appointment as America's handpicked man for the job. It is these chinks in his armour that make him a difficult person to defend in the eyes of the average Iraqi.