On Fox Business News this evening former judge Andrew Napolitano stated that letters of marque and reprisal are to be issued by the president to private actors. that is incorrect.
See http://constitution.org/mil/lmr/lmr.htm for more on the subject. They do not have to be issued to private actors, and Congress may not delegate the issuance to the President. It must issue LMR directly, and could appropriately do so to the President and forces under his command.
The several authorizations to use military force (AUMF) are similar to LMR, but are missing key elements, such as greater specificity concerning who may be targeted.
However, there are also two other constitutional powers that apply to such cases: the power to punish piracy and offenses against the law of nations, under which "pirates" are treated as a special case, as "enemies of all humanity" who may be killed wherever they are found. What we call violent "terrorists" are essentially what the Constitution calls "pirates" -- nonstate actors who commit unauthorized warlike acts against targets foreign to themselves. (If against their own it is "treason".) The historical legal precedents are for pirates to be tried in the field by military tribunals, which could be captains of sea vessels and the senior officers, and summarily executed if found to be pirates or closely associated with them.
That legal legacy obviously has problems for due process and is open for abuse, however, that is the legal tradition incorporated into the Constitution.
I have proposed an amendment to clarify the point:
- Clarification of "piracy"
- "Piracy" shall consist only of warlike acts committed by a foreign nonstate actor, or by a domestic nonstate actor against foreign persons or property. Letters of marque and reprisal make the person to whom they are issued a state actor, and under a declaration of war all citizens are to be regarded as state actors with respect to the foreign state defined in the declaration.