"Either they did not want to or they could not do it," he said. He now suspects the US and its ally Pakistan deliberately sowed chaos in Afghanistan to justify the lingering presence of foreign forces - now numbering around 15,000 - in order to use the country as a listening post to monitor Iran, Russia and China.
"They have made a hell, not a paradise for us," he said.
Afghanistan is rife with such conspiracy theories. After last month's assassination of Kandahar's powerful police chief, General Abdul Raziq, social media exploded with pictures and posts suggesting he was the victim of a US conspiracy. Recent insider attacks, in which Afghan forces have killed their erstwhile US and Nato allies, have attracted online praise.
"In 2001 the Afghan people supported the arrival of the United States and the international community wholeheartedly," said Hamid Karzai, who was installed as Afghanistan's first President and twice won re-election, serving until 2014.
"For a number of years things worked perfectly well," he said in a recent interview. "Then we saw the United States either changed course or simply neglected the views of the Afghan people and the conditions of the Afghans." He blames the lingering war on the US failure to eliminate militant sanctuaries in neighbouring Pakistan, the bombing of Afghan villages and homes, and the detention of Afghans in raids.
Others blame the notoriously corrupt Government, which Karzai headed for more than a decade, and which is widely seen as yet another bitter fruit of the American invasion.
"All the money that has come to this country has gone to the people in power. The poor people didn't get anything," said Hajji Akram, a day labourer in Kabul who struggles to feed his family on around US$4 a day. "The foreigners are not making things better. They should go."
It's not just Afghans. The US inspector general for Afghanistan's reconstruction offered a blistering critique in a speech in Ohio this month.
John Sopko pointed out that the US has spent US$132b on Afghanistan's reconstruction - more than was spent on Western Europe after World War II. Another US$750b has been spent on US military operations, and Washington has pledged US$4b a year for Afghanistan's security forces.
The result?
"Even after 17 years of US and coalition effort and financial largesse, Afghanistan remains one of the poorest, least educated, and most corrupt countries in the world," Sopko said. "It is also one of the most violent."
Hamidullah Nasrat sells imported fabrics in the capital's main bazaar on the banks of the Kabul River, a fetid trickle running through a garbage-filled trench. He remembers welcoming the overthrow of the Taliban, who had shut down his photography studio because it was deemed un-Islamic.
"After the Taliban we were expecting something good, but instead, day by day, it is getting worse," he said. "How is it that a superpower like the United States cannot stop the Taliban? It is a question every Afghan is asking."
The US and Nato formally concluded their combat mission in 2014. Since then, the Taliban have carried out near-daily attacks on rural checkpoints and staged co-ordinated assaults on major cities.
Authorities stopped publishing casualty figures this year, deeming them classified. An Isis (Islamic State) affiliate has meanwhile carried out massive bombings against the country's Shia minority.
Afghans who have recently served on the frontlines complain of faulty equipment, inadequate supplies and reinforcements that show up late and ill-equipped, if at all.
Tameem Darvesh served in the Afghan army for nearly five years in the southern Helmand province. This year he went on holiday and never returned, trading his US$180 monthly salary for work as a day labourer making much less. He said morale is at an all-time low, with many soldiers now expressing sympathy for the Taliban.
- AP
