If one individual could bring peace to Afghanistan, US envoy Zalmay Khalilzad touted himself as the man for the job.

In the end, however, the seasoned diplomat has overseen the demise of the republic he so painstakingly assembled.

The 70-year-old Afghan-American envoy spent years as Washington's point man for talks with the Taliban that paved the way for the deal to see the US end its longest war and exit Afghanistan.

That milestone came after more than a year of intense shuttle diplomacy during which Khalilzad visited foreign capitals, attended summits at glitzy hotels, and gave speeches at prestigious think tanks.

The Taliban were ready to discuss a compromise, he assured his audiences.

Once a prolific social media voice, Khalilzad has gone silent since the Taliban returned to power following the collapse of the US-backed government in the face of an overwhelming blitzkrieg.

The State Department said last week the envoy remained in Qatar, working the phones in hopes of encouraging a diplomatic settlement.

But the deal he had hoped could end the war had actually unleashed disaster.

Khalilzad was said to have developed a close rapport with the Taliban delegation
Khalilzad was said to have developed a close rapport with the Taliban delegation AFP / Giuseppe CACACE

Husain Haqqani, a senior fellow at the Hudson Institute, said Khalilzad told successive US presidents eager to withdraw their troops that he had a peace deal, but it was in fact a surrender.

"He negotiated poorly, emboldened the Taliban, and pretended that talks would yield a power-sharing agreement even though the Taliban had no intention to share power," Haqqani told AFP.

Khalilzad took control of the US-Afghan portfolio in 2018 after the Trump administration named him a special envoy overseeing negotiations with the Taliban.

The new assignment followed a storied career. Khalilzad had shaped embryonic governments in Afghanistan and Iraq following successive US invasions, gaining a reputation for bringing disparate groups to the table.

Washington's decision to pursue talks followed years of rising violence in Kabul where the Taliban unleashed chaos by sending waves of suicide bombers into the Afghan capital.

Khalilzad secured the release of the Taliban's co-founder Mullah Abdul Ghani Baradar from Pakistan's custody to kickstart the initiative, with the two sides cobbling together an agreement charting the US withdrawal after nearly two decades of conflict.

During months of negotiations in Qatar, Khalilzad was said to have developed a close rapport with the Taliban delegation.

Zalmay Khalilzad spent years as Washington's point man for talks with the Taliban
Zalmay Khalilzad spent years as Washington's point man for talks with the Taliban GETTY IMAGES NORTH AMERICA / ALEX WONG

Pictures published online showed the gregarious envoy sharing laughs and smiles with insurgent negotiators, stirring resentment in Afghanistan where the war raged.

But when the US withdrawal deal was finally signed in February 2020 at a lavish ceremony in Doha, Khalilzad had secured mostly nebulous assurances from the Taliban about any future peace.

"Khalilzad prised... just one strong commitment -- that they would not attack the US and 'its allies'," wrote Kate Clark of the Afghanistan Analysts Network in a new report.

More vague were promises from the Taliban to abandon Al-Qaeda and other international jihadist groups, and to begin talking to the Afghan government.

In hindsight, the agreement appears to have been little more than a string of American concessions.

The US was leaving Afghanistan without a ceasefire and had not even established a framework for a future peace process that would be vital for locking down a settlement to end the war.

Rather than securing compromises from the Taliban in the months following the deal, Khalilzad piled more pressure on the Afghan government -- strong-arming the palace into releasing thousands of insurgent prisoners who immediately bolstered the militant ranks.

To add to Kabul's woes, the agreement effectively set off a countdown, with the US promising to pull all of its remaining troops from Afghanistan by May 2021 -- a deadline later extended until September.

The Afghan government was left with little time or space to manoeuvre.

US President Joe Biden's decision in April to follow through with the withdrawal lit the final fuse, sparking an all-out offensive by the Taliban that overthrew the Afghan government by force on August 15.

Two days earlier, US lawmaker Michael Waltz -- an Afghan veteran -- sent a letter to Biden pillorying Khalilzad's performance.

Khalilzad "has provided you with poor counsel and his diplomatic strategy has failed spectacularly", he wrote.

"In light of this catastrophe, Ambassador (Khalilzad) should resign immediately or be relieved from his position."

That same day, Khalilzad sent out his last tweet -- begging the Taliban to pull back its fighters as they converged on Kabul.

"We demand an immediate end to attacks against cities, urge a political settlement, and warn that a government imposed by force will be a pariah state," the envoy wrote.

By then, it was too late.