Peace efforts in Afghanistan are likely to fail if they do not include all militant groups, a senior member of one of the country's most notorious insurgent factions said on Sunday. "If any group is isolated or ignored, that group then becomes the centre of the resistance, and can cause problems," Ghairat Baheer, of Hizb-i-Islami, told Reuters in Islamabad.
"To bring instability or disturb the situation of Afghanistan is not difficult. It is very easy."
Hizb-i-Islami, which means Islamic Party, is a radical militant group with widespread national support in Afghanistan, shares some of the Afghan Taliban's anti-foreigner, anti-government aims, and wants to oust international forces.
The group, led by Afghan warlord and former prime minister Gulbuddin Hekmatyar, claims to have thousands of fighters in its ranks, based mainly in Afghanistan's restive east, bordering Pakistan, and in the north.
The US State Department lists Hekmatyar as a "terrorist" for supporting Taliban and al Qaeda attacks, but US and Afghan officials have met with Hizb-i-Islami representatives in the last two months to help end the war, now in its eleventh year.
"There is communication, and there is negotiation going on between Hizb-i-Islami and the American and Afghan governments," Baheer, Hekmatyar's son-in-law.
Hekmatyar is a fierce rival of Taliban leader Mullah Omar, and became a hero to many Afghans while leading mujahideen fighters against the Soviet occupation of Afghanistan in the 1980s.
In the early 1990s, forces led by Hekmatyar opposed to the government of then-president Burhanuddin Rabbani took part in fighting in Kabul which is thought to have killed tens of thousands.
Hekmatyar left Afghanistan in the mid-1990s and his whereabouts have been unclear since then.
The Afghan Taliban announced last month it would open a political office in Qatar, suggesting the group may be willing to engage in negotiations that could give it government positions or official control over much of its historical southern heartland.
While the Taliban are the focus of media attention, there are a number of other militant organisations that want a say in Afghanistan's future.
They include the al-Qaeda linked Haqqani network, one of the most feared Afghan insurgent groups blamed for many high-profile bombings.
While the Haqqani group has pledged allegiance to the Taliban leadership, it also exercises significant operational independence.
Failure to appease these groups could bring prolonged instability, or even civil war, once Nato combat forces withdraw in 2014.
"There should be a comprehensive solution involving all parties and groups," said Baheer, a doctor by training.
Baheer, who was held in US detention at Bagram Air Field, north of Kabul, for six years until his 2008 release, said he had not seen enough progress in US-Taliban talks to suggest they were any closer to formal negotiations.
"So far they have not been able to agree on even minor issues that could be taken as goodwill gestures. There's no official inauguration of the (Taliban) office, there is no release of prisoners and no one has been removed from the blacklist," he said.
"Things are stuck. We are also in a wait and see situation."