Geneva Convention.
In the general interests of reader knowlege, this link is posted.
Do particularly note the bit about taking hostages, and the bit about engaging in directly war-supporting work on the premises of a hospital.
And also the bit about uniforms, ID, orders of a clearly-identified superior, etc.

I am off tomorrow, back to the Enormous Corporate Behemoth, on a well-paid temp assignment for the remainder of the month, which will keep the wolf from the door (or at least, at the bottom of the driveway) while an interested agent looks over the first third of “To Truckee’s Trail”.
Ta, then!