The United States spent more than a decade and tens of billions of dollars arming and training the Afghan National Security Forces (ANSF) to fight the Taliban.
As a core part of NATO's strategy to gradually transfer power and withdraw from Afghanistan, the ANSF took control of the country's security late last year, and have since led the fight against the armed group.
But in August 2014, 15 civilians were killed and 13 others wounded when a joint US-Afghan special forces operation targeting the Taliban went wrong.
Fault Lines has conducted a year-long investigation to piece together what happened that day in Charkh district.
In this exclusive film we gather eyewitness testimony detailing abuses by Afghan forces - and raising questions about who is ultimately to blame.
Source: Al Jazeera