Afghanistan will not unravel into a civil war after the withdrawal of NATO combat troops in two years or return to Taliban rule, a senior NATO diplomat said Monday.

The planned departure of the bulk of US and NATO troops by the end of 2014 has prompted gloomy forecasts of an internecine war pitting proxy forces backed by Pakistan and India.

But NATO's senior civilian representative, Simon Gass, rejected those predictions, arguing Afghan security forces were too strong for the Taliban and that regional powers had no interest in a return to the "dark days" of the 1990s.

"I really don't buy the (civil war) scenario. I think some people find it an attractive scenario because it looks like history rewriting itself," Gass told AFP and Fox News in an interview in Kabul.

"I really don't think that will happen. One of the reasons it won't happen is because Afghanistan's neighbours realise the huge amount of problems that they would face if Afghanistan were tipped into a position of constant conflict and chaos," he said.

Full-blown civil war would result in a massive flow of refugees out of Afghanistan, he said.

"I really don't think any of Afghanistan's neighbours would welcome the instability in this region that would be triggered by that sort of scenario."

He said said Afghan leaders from all parts of the country all desperately want to avoid a return to the anarchy and bloodshed of the 1990s.

"There is one thing that comes across quite strongly, I would describe it as horror at the idea of returning to the dark years, '92 and '93, when the civil war was raging and shells were falling on Kabul.

"Nobody wants to go back there."

Although he acknowledged the Taliban insurgency remains a resilient force that could stage bombings and disruptive assaults, he said the Islamist militants could not defeat Afghan government forces in a direct confrontation.

"I don't know anybody who thinks the Taliban have the military strength to overturn the Afghan security forces," said Gass, a British diplomat and former ambassador to Iran.

"The Taliban don't have anymore the ability to get back into their Hiluxes and drive back into Kandahar. It's just not feasible," he said, referring to the Islamists' former stronghold.

He said that "in order to return to power, the Taliban have to mass.

"If the Taliban mass, they can be hit. That's their fundamental problem. You can't imagine them having success against the ANSF (Afghan national security forces) on the battlefield."

But he acknowledged that Haqqani militants, which stage attacks in eastern Afghanistan from sanctuaries inside Pakistan, remained a serious threat that would require Pakistan's help to counter.