Crimes committed by a US Citizen on Foreign Soil should be subject to trial in the jurisdiction where the crime was committed.
Numerous examples can be found of US Citizens committing crimes abroad and being tried or extradited to be tried in foreign countries.
Our relationship with Afghanistan will suffer if we do not return the alleged criminal, military or otherwise, back to Afghanistan to face trial.
His actions were not by direction of any military order and he was not acting as an agent of the US Military and therefore should be treated like a civilian.
Show the people of Afghanistan that the US is a fair and just nation. We have been arresting, trying, and convicting it's citizens of crimes in our courts. Give them the same privilege.