WEEKEND violence in the western city of Herat is a reminder of how volatile the situation in Afghanistan remains, three years after the US overthrew the Taliban and less than four weeks before presidential elections there.

George Bush described Afghanistan last June as "the first victory in the war on terror". A year ago, the US Defence Secretary Donald Rumsfeld declared that major combat operations were over and an era of stabilisation and reconstruction had begun.

But despite some progress in education, health and infrastructure, Afghanistan remains far more unstable than western leaders care to admit. Afghanistan is a nation-building challenge to which even Iraq pales in comparison.

Attacks attributed to a resurgent Taliban and its Al Qaeda allies have claimed more than 1,000 lives in the past 12 months. Low-level conflict in the south and east has become the norm. Foreign aid workers have been repeatedly targeted, as in Herat on Sunday. Much of the country beyond Kabul is considered insecure.

Major General Eric Olson, the operational commander of US forces, admitted at the weekend that his troops were "not even close" to defeating the insurgents. The 14,000-strong Afghan national army, prone to high levels of desertion, is struggling to make an impact.

Parallel efforts to disarm Afghanistan's more numerous mujahideen militias - a precondition for elections, according to the 2001 Bonn accords - have stalled. US forces in Afghanistan total 18,000, compared with 130,000 in Iraq.

Up to 10,000 Nato troops are attached to the separate international security force, Isaf. For some, that disparity suggests a lack of US commitment. The previously delayed elections, due on October 9, are beset by similar concerns.

Afghans have shown considerable enthusiasm for the polls, registering in large numbers. About four million women are expected to cast a ballot - a revolution in the Afghan context. If they wish, they can even vote for a female candidate, Massouda Jalal.

But security will be a big worry, with Taliban already assassinating election workers and vowing to wreck the process if they can. Over-stretched western forces cannot possibly guarantee a safe and fair poll nationwide.

Fraud and intimidation are also potential problems. Only a few hundred foreign observers will be on hand to monitor 25,000 polling stations. Western governments are nevertheless keenly anticipating a democratic triumph in Afghanistan next month - and are likely to declare one, almost whatever happens.

Mr Bush and Tony Blair, facing their own elections, draw from the Afghan electoral process a powerful vindication of their policies. Similar considerations apply to polls planned for January in Iraq.

Western leaders are also counting on a victory for Hamid Karzai, Afghanistan's pro-western ethnic Pashtun leader and the man they installed after 9/11. That remains the most likely result, possibly after a second round of voting.

But Mr Karzai must first see off 17 challengers, the foremost of whom is Yunus Qanuni, an ethnic Tajik who has become, in effect, the candidate of the Northern Alliance warlords who seized Kabul with US backing in 2001.

Mr Karzai is a nationalist in a country where nationhood and national unity are still novel concepts. Should he win, his main task will be to extend his power beyond Kabul by curbing the mujahideen.

This is the key to stamping out corruption and the multi-billion dollar trade in opium poppies; and to moving on successfully to parliamentary elections next spring. And this, in a symbolic way, is what Mr Karzai's weekend removal of Ismail Khan, the warlord governor of Herat, was all about. The violent reaction there may be a sign of things to come.

Since 2001, the US has followed an improvised political strategy in Afghanistan, ostensibly promoting national self-determination while maintaining ad hoc alliances with the mujahideen.

The challenge facing Mr Karzai is thus how to wrest control of his country not only from warlords and insurgents, but also, ultimately, from the American puppet-masters who have manipulated both them and him.

The penalty for failure is a descent into renewed violence; or what into what one analyst, Kathy Gannon, calls a failed "narco- state", spinning rapidly out of control. -Dawn/The Guardian News Service.