The Taliban, remember them? These days, what with the Islamic State (IS) group hogging the headlines it’s easy to forget that the Taliban in both Afghanistan and Pakistan continue as a force to be reckoned with.

Just how difficult they are to contain let alone eradicate as a fighting force inside Afghanistan I was reminded of this week, with the news that the militants had seized control of as many as 80 villages in Afghanistan’s northern province of Kunduz.

It is fourteen years now since I watched as the Taliban in that same location were routed by a combination of Afghan Northern Alliance soldiers backed up by US airstrikes. Some of these Taliban chose at the time to defect rather than be pulverised by the payloads of American B52 bombers dropped on the villages of Khanabad and Amirabad surrounding Kunduz.

Led by a commander called Mullah Najibullah, and dressed in their distinctive black turbans, his fighters arrived at our lines still carrying their Kalashnikovs, and packed in jeeps and trucks plastered with mud as camouflage against American warplanes.

Despite their defection there was no mistaking their defiance. One, on realising I was British, ran his finger across his throat in a threatening gesture and laughed along with the Alliance soldiers who up until that moment had been their sworn enemy, but suddenly appeared the best of friends

That defiance has been a hallmark of the Taliban over the years. Yesterday the world was reminded of it yet again with the news that the group had appointed a successor to Mullah Omar, their leader who was confirmed dead by the Afghan government on Wednesday.

It was a defiant gesture not just in itself but in the choice made in Mullah Akhtar Mohammad Mansour. That Mansour was not the first choice of many senior Taliban commanders is a given. Though he was Omar’s deputy, many would have preferred to have seen Omar’s 26- year-old son, Yaqoob succeed him. This young firebrand of course is opposed to any peace talks.

A former aviation chief in the Taliban government that led Afghanistan from 1996 to the 2001 US invasion, the group’s newly appointed Supreme Leader,

Mansour has risen up through the Taliban’s ranks.

If there is any good news associated with his appointment it is that Mansour is pro-talks. The bad news is that the uncertainty and potential friction sure to follow his takeover will most likely throw into disarray any such talks and a fledgling peace process aimed at ending more than 13 years of war between the Taliban and the Western-backed Afghan government in Kabul.

This was immediately underscored yesterday by an announcement from the Pakistani foreign office that a planned second round of meetings set for today were postponed at the request of the Taliban leadership.

Among those said to be disgruntled by Mansour’s appointment are the movement’s top military chief, Mullah Qaum Zakir, as well as Tayeb Agha, the head of the Taliban's political office in Qatar, and Mullah Habibullah, a member of the group’s Quetta shura or ruling council.

That a potentially bloody succession battle has been avoided thus far might seem like a positive sign, but there is no avoiding the fact that some key commanders remain opposed to the peace process vowing instead to fight for power, rather than negotiate it.

Many analysts point to the influence of pro-Pakistani circles within the Taliban of imposing Mullah Mansour as the new leader.

Indeed the relationship between the Afghan Taliban and its counterpart on the other side of the border Tehrik-i-Taliban Pakistan (TTP) is a complicated one fraught with its own tensions.

Yesterday’s appointment too of Siraj Haqqani as deputy to Mansour only further adds to the intrigue and volatile mix.

Siraj is already leader of what is known as the Haqqani network, a powerful grouping that while officially subsumed under the larger Taliban umbrella organisation, maintains it own distinct command and control, and lines of operations.

Siraj is the son of Jalaluddin Haqqani who was well known as a guerrilla commander during the war against the Soviet occupation in the 1980’s.

Unlike his father though, Siraj is of a more extremist disposition and leans towards al-Qaeda and other foreign extremists in Pakistan. For this reason it’s hard to see him falling behind any calls by Mansour to continue talks with the Afghan government. This would almost certainly lead to a new phase of uncertainty for Washington and its allies in the region.

But beyond peace talks, there is another even more worrying dimension to this ongoing Taliban reshuffle.

While the brutality of the Taliban and its chiefs past and present remains medieval, their style of leadership held the group together. Significantly too, their strategy has been very different from that of the worlds other headline grabbing Islamist group, Islamic State (IS).

Useful as that positioning is for any prospective peace talks it does not however sit well with the hotheads among the younger generation of Taliban. Not only are they opposed to negotiations and peace talks but perceive their group as being eclipsed by IS.

And here lies the biggest threat of all, a fractured Taliban where many of their disgruntled fighters chose to defect and take up arms with IS.

Already there have been instances of these hardliners declaring allegiance to IS and engaging in gun battles with traditional Taliban groups.

Could it be then that events of the last few days signal the beginning of the rise of IS out of the disintegration of the Taliban? If this proves to be the case it is the worst possible news for Afghanistan the wider region and the West.