I remember reading that Afghan mechanics could fix Russian helicopters because they had experience in fixing them. But Americans decided to get rid of them and bought our helicopters for the Afghan Air Force. We all know the ending to that story.
It makes sense in terms of keeping some measure of control over the Afghan military; when Iran’s Shah was deposed some nice modern jets sat unused during the Ayatollah’s reign because we wouldn’t service them or provide parts. In their 8-year war with Iraq, it could have been a game-changer...