The pentagon is part of the executive, not the legislative, and as such they can not write the 'rules' (law)

The executive also can’t declare war, yet we are in Iran. Executive orders have stood in for legislation; even though it shouldn’t.

What is considered lawful is up to the whims of the pentagon and the other two branches have shown little interest in providing sufficient checks and balances. Maybe 5 years after the pentagon makes an illegitimate legal justification will a judge strike it down: that is if we are lucky.