Call them what you will. They are military attacks against military targets. We can debate the appropriateness of particular measures in given situations, like whether or not drones should be used, but I don't think there's a reasonable argument to be made that members of paramilitary organizations that are dedicated to our destruction should not be treated as military targets.
As to why the memo was necessary, I see it as a memo limiting, not expanding executive power. The memo spells out when the Executive must treat an American member of a terrorist organization as a criminal, and not a military target.
Why the secrecy, if this were really as uncontroversial and cut and dry as you assert? Why would they deny the existence of a document granting additional rights to American citizens in standard engagements?
Your reading of this memo is ludicrously generous.
I disagree. As CiC, the President has total authority over the conduct of military campaigns. This memo limits that authority and describes under what circumstances military power may be used.
As to why the memo was necessary, I see it as a memo limiting, not expanding executive power. The memo spells out when the Executive must treat an American member of a terrorist organization as a criminal, and not a military target.