It is also the US’s longest overseas military action, vexing three successive US presidents.
Officials, diplomats and analysts say that although getting both sides to the negotiating table was an achievement in itself, it does not mean, however, that the path to peace will be easy.
“The negotiations will have to tackle a range of profound questions about the kind of country Afghans want,” Deborah Lyons, the UN special representative for Afghanistan, told the UN security council this month.
The talks opened with an inauguration ceremony that was to be attended by US Secretary of State, Mike Pompeo. It is taking place a day after the 19th anniversary of the 9/11 attacks on the US that triggered its occupation of Afghanistan.
US forces intervened in Afghanistan on the orders of president George W Bush a month after the attacks to hunt down their mastermind, Osama bin Laden, a Saudi who had been given sanctuary by the country’s radical Taliban rulers. They initially offered mainly air support to the Taliban’s local enemies.
The Taliban regime was quickly toppled, but they regrouped and have since waged an insurgency that has sucked in Afghanistan’s neighbors and troops from dozens of countries, including NATO forces.
Negotiations to broker a comprehensive peace deal were envisaged in a troop withdrawal pact signed between the US and the Taliban in February in an attempt to find a political settlement to end the war.
After months of delay, a dispute over the Taliban’s demand for the release of 5,000 prisoners was resolved this week.