The sheer scale of the American firepower now being drafted into southern Afghanistan to take on the Taleban - who generally fight in flip-flops with a Kalashnikov in their hand - might convince some people that this enemy is going to be defeated by superior weaponry and ground manoeuvre warfare.

But it has not worked yet, not in the eight years the US-dominated forces have had to try to rid Afghanistan of the Taleban threat. Now, however, under a troop-reinforcement programme started by George Bush and expanded significantly by Barack Obama, the plan is to flood key parts of the south, where the Taleban have greatest influence and control, with thousands of US Marines and other American combat units. After seizing the territory they would hold it with the help of the burgeoning Afghan National Security Forces (ANSF) and coalition troops, such as the British, who have already been in the south for three years.

The difference between the Americans and the Russians - who deployed more than 100,000 troops to Afghanistan and killed thousands of civilians with bombs and helicopter gunships fighting the Mujahidin in the 1980s - is that the US and the rest of the coalition are determined to use their superior firepower and ground manoeuvre tactics to create safe, Taleban-free zones of population. In those areas rapid construction projects - roads, government buildings, improved electricity - and agricultural programmes can be introduced to change the lives of the Afghan people for ever. Such zones already exist but they are now to be expanded into new areas.

For the average poppy farmer living in a remote compound who makes a reasonable wage for his family from his illicit crops, the influx of American troops - 17,700 combat and 4,000 ANSF trainers - has little relevance. He needs security to keep his family from harm and if the vast apparatus of Nato's International Security Assistance Force (ISAF) cannot guarantee it, he will turn to the Taleban who enforce law and justice ruthlessly but effectively. Even the most enlightened Afghans, such as Galali Assanfoor, principal of Malalai High School for Girls in Lashkar Gah, provincial capital of Helmand, admitted to The Times that under Taleban rule there was “proper” security.

However, as part of the grand plan to spread US Marines and other American units into the four provinces of southern Afghanistan - Helmand, Kandahar, Oruzgan and Zabol - the objective is to provide “relative security” for 90 per cent of the population in the larger communities. Three thousand Marines from the 2nd Marine Expeditionary Brigade will cover the area from Garmsir in southern Helmand down to the Pakistan border; the Striker Brigade, a fast-moving armoured unit, will operate in Kandahar and Zabol; and the US Combat Aviation Brigade will give extra offensive capability in all four provinces. To underline the scale of the American influx of troops and weapon power, there will be a 250 per cent increase in helicopters operating in ISAF's Regional Command South by the time the US arrivals have been completed, and total troop numbers will rise to 42,000 from the present 22,300.

What is unknown is how the Taleban are going to react to this increase in American troop numbers. Until now, the insurgents have managed to create a stalemate in the south, particularly in Helmand, by resorting to asymmetric warfare, replacing conventional attacks with the planting of huge numbers of improvised explosive devices (IEDs) in the so-called green zone of poppy and wheat fields and in the desert areas where British vehicles ferry troops between forward operating bases. As Brigadier David Hook, a Royal Marine and deputy commander of Regional Command South (RCS), told me, the Taleban resorted to IEDs because every time they take on the security forces, they are comprehensively defeated.

The IED and the suicide-bomber threat, both of which are expected to increase over the summer months, are a daily menace for ISAF troops and for civilians who suffer the brunt of the casualties. The roadside bombs will have to be countered at source, by focusing military effort on the suppliers of the explosive devices and the networks who distribute them.

The four southern provinces were targeted with 247 IEDs last month. Although ISAF has become better at finding and defusing these devices, they remain a hindrance not just to military operations but, more importantly, to the civilian programmes upon which the so-called “comprehensive” strategy for Afghanistan depends.

All Afghan officials working to spread local governance in their province bemoan the fact that they are still hampered by the threat posed by the Taleban wherever they go. One example is Wahedullah Ulfat, who is 22 and a technical adviser to Alhaj Gulab Mangal, the Governor of Helmand, based in Lashkar Gah. He faces regular death threats by e-mail and by phone, and the other day he was riding his motorcycle home when he was shot at. “I had my gun on me and fired back. I was all right,” he recalls.

Due east in neighbouring Kandahar, the huge and expanding airbase from which daily air operations are launched hosts 175 fixed-wing jets and helicopters, rising over the next few months to 400. As a demonstration of firepower they are unmatched and play a vital part in protecting ground troops under fire. But for the likes of Mr Ulfat, a dedicated civil servant determined to serve the governor despite the threats to his life, all the firepower and all the high-tech wizardry available to the Americans at Kandahar will never guarantee him the security he needs to fulfil his duties.

The military fully accept that the point of the campaign is not to defeat the Taleban. Indeed, some military commanders have come out publicly to say that the Taleban cannot be defeated. The thousands of extra troops now flying into Afghanistan will undoubtedly fight the Taleban and intend to drive them away from the population areas. But the successes they achieve on the battlefield will be judged, not by the number they kill or capture, but by the opportunities their tactical victories will create for the Afghan people to improve and change their lives for the better. If removing the Taleban from the heartland of Helmand and the other southern provinces spreads democratic government to this region, then the military campaign can be classed a success.

Michael Evans is the defence editor of The Times

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