The Secretary of the Army cannot make such a ruling, he does not have operational control of any troops in Afghanistan. This comes from the operational chain of command in the theater.
Don’t know if this makes sense, depends on the conditions on the ground. I sometimes did this as a rifle company commander in Vietnam based on where we were and who was around. Biggest problem with rounds in the chamber is some knucklehead who takes his weapon off safe and accidently shoots a buddy. Not good.
If you have knuckleheads like that out on a patrol, and you know it, you didn't train them well enough or the Army send you some real damn dregs.