Kim Sengupta: It worked in Iraq, but success in Afghanistan is less certain

Petraeus is under intense pressure after Western leaders outlined a withdrawal timeline to appease voters

The setting up of the "local defence forces" in Afghanistan should not come as too much of a surprise following the arrival of General David Petraeus to take charge of this war. He used similar groups, with a degree of success, during the "surge" in Iraq, which contributed to the insurgency being set back.

Unlike Iraq's "Sunni Awakening", the bands in Afghanistan will not be composed of militants who have "turned" and will instead be raised from tribal levies. However, a parallel project of attempting to reconcile the lower-level Taliban is also under way and the "local defence forces" may well be the groups they will join in the future.

There are significant pitfalls to General Petraeus's plan. President Karzai had been vehemently opposed to the strategy and is even now said to fear that the armed groups will be used by regional strongmen to their own ends. (One could point out, of course, that is precisely what his brother, Ahmed Wali Karzai, is accused of doing in Kandahar.)

It is true that attempts to form "volunteer forces" in the past have not been a success, spawning tribal rivalries and extortionate behaviour from the licensed gunmen. In some cases it has even led to the public, who became the militias' prey, switching their allegiances to the Taliban insurgency.

General Petraeus and his commanders are under intense pressure, created mainly by political leaders in the West (led by US President Barack Obama and followed by Prime Minister David Cameron) putting down a timeline of withdrawal to appease their increasingly tetchy electorates.

Conscious of inheriting a war where the Taliban and their Pakistani backers sense a weakening of resolve among Western leaders (which has led to a spike in the level of insurgent violence with the aim of hastening the date of Western departure) General Petraeus is falling back on strategies which helped him in Iraq, the scene of what is regarded as his triumph.

But Afghanistan is not Iraq and it is a big gamble to introduce more men with guns at this stage into the arena. We shall find out soon enough whether Gen Petraeus has kept his counter-insurgency "golden touch".