To add to that, before the troops were leaving the Sikh and Hindu communities in Afghanistan had to pay a jeziah tax, a special tax to the Taliban, in order to survive. When ISIS came in different parts of Afghanistan, they had to pay ISIS. The tax is utilized by these terrorist organizations to not only persecute these minorities, but under their law determine a way to kill them, as in they will raise the tax to a point where these people cannot pay and then in their eyes it's okay to go and target these people for killing. It's also a way to fund their crime and continue to fund their terrorism.
As the troops are departing the situation is going to escalate. These folks, just like the professor mentioned, will continue to get a larger amount of tax. They will continue to be persecuted not only for symbolic reasons that they're maintaining control but also to finance the terrorism.