We do give them due process as a normal procedure, but technically it is not required by law. They can get due process from where they came from. You are applying civil rights to non citizen foreign enemy combatants is what you are advocating.
Just remember who dies after their army is gone, those that thought they were protected should the SHTF.
President Trump and the DOJ have to look into this because this could negate the 200 or so advocate judges moot without a argument. The 13th Amendment.