LONDON: The world should give the Taliban the space to form a new government in Afghanistan and may discover that the insurgents cast as militants by the West for decades have become more reasonable, the head of the British army said on Wednesday.

The leaders of the Taliban will show themselves to the world, an official of the Islamist movement said on Wednesday, unlike during the last 20 years, when its leaders have lived largely in secret.

Nick Carter, Britain's chief of the defence staff, said he was in contact with former Afghan President Hamid Karzai who Carter said would meet the Taliban on Wednesday.

"We have to be patient, we have to hold our nerve and we have to give them the space to form a government and we have to give them the space to show their credentials," Carter told the BBC. "It may be that this Taliban is a different Taliban to the one that people remember from the 1990s."

"We may well discover, if we give them the space, that this Taliban is of course more reasonable but what we absolutely have to remember is that they are not a homogenous organisation - the Taliban is a group of disparate tribal figures that come from all over rural Afghanistan."

Carter said the Taliban were essentially "country boys" who lived by the so called "Pashtunwali", the traditional tribal way of life and code of conduct of the Pashtun people.

"It may well be a Taliban that is more reasonable," Carter said. "It's less repressive. And indeed, if you look at the way it is governing Kabul at the moment, there are some indications that it is more reasonable."

Some British army veterans, though, were doubtful.

"People should not be seduced by these smooth words,” Charlie Herbert, a former British army major general who served in Afghanistan and also worked as a senior NATO adviser, told Sky News.

"The Taliban need international recognition. They’ve taken power by force and they’re now desperate for international recognition, from China, from Russia and the West, they need that. So of course they’re going to use these charming words about equal opportunities for women," he said.

Herbert said there is no evidence the Taliban has moderated.

"They are waiting, they are biding their time until we leave Kabul and then the bloodletting will start when there are no journalists and no internationals to see it."