In recent years, a key rationale for continued US involvement in Afghanistan, its longest ever war, is that once the Taliban have been pushed onto the back foot, they would be prepared to come to the negotiating table. Weakened rebels would be ready to compromise.

The reality, of course, is that with each new fighting season, the Taliban are getting stronger. Most NATO troops have withdrawn leaving the Americans. Foreign instructors still train Afghan police and army but military analysts accept that but for the US intelligence and air strike capacity, along with its command and control systems, the Taliban would probably have marched into Kabul by now.

Thus this week’s offer by Afghan president Ashraf Ghani of unconditional talks with the Taliban would appear to be too little and far too late. On the face of it, there is no good reason why the Taliban should be talking to anyone. They are steadily increasing their grip on the country, outside of the major urban areas. And even the cities are not safe. The 2015 attack on the heavily-fortified Kandahar airbase killed scores of government soldiers and the assault on the north of the city, two years later was an even more devastating humiliation for the Ghani government.

Yet there is a glimmer of hope for Ghani’s offer of talks, even if it does not bear immediate fruit. There is no single Taliban. In the past, tribal leaders who had given their support to the rebellion were still prepared to talk. Perhaps one of the most culpable failures of Ghani’s predecessor, Hamid Karzai, was to explode with very public anger when he chose to discover that the British were in serious talks with some tribal leaders in Helmand Province. It is thought that Karzai was well aware of the UK initiative. His decision to scotch the talks and to expel the British Afghan experts who had been leading them had much to do with his fear of being sidelined by the foreign powers who were defending his government. The paranoid Karzai, who used to complain how cut off he was in his heavily guarded Kabul palace, had a good line in outrage.

The Taliban has not changed. It remains shot through with rivalries and jealousies, many of which predate the arrival of the late Mullah Omar and his Taliban banner. In particular, there are leaders who object to the presence of all foreigners, not least the followers of Daesh (the self-proclaimed IS) who have been playing an increasingly active role in attacks on government forces. Iraq and Syria may be all but lost to them, but the mountain strongholds of Afghanistan once again offer a relatively safe base for Daesh killers. They doubtless calculate that a return of Taliban rule would restore their privileged position in the country, destroyed by the US-backed Northern Alliance in December 2001.

That month of triumph was also the month of tragedy. The Bonn conference in Germany gathered the victors along with international donors who pledged billions for the rebuilding of the country torn apart by civil war since 1978 and the Soviet invasion the following year. But in what is now clear was an appalling error, the vanquished Taliban were excluded from the talks. More than 100,000 Afghans have since died, a third of them civilians. Will Taliban leaders now agree to end the bloodletting?