The “war on terrorism” is fundamentally a misnomer, because “War” is a constitutional term of art; and “the war on terrorism” has not been, and due to the diffuse nature of the enemy and undefinable character of the conflict cannot be “declare[d]” as the Constitution prescribes. (footnote 1) Constitutionally speaking, “War” is a specific set of legal relations between two or more independent nations. For the most obvious example, in an actual “War” soldiers in one nation may, within certain limits, intentionally kill soldiers of another nation without thereby being guilty of murder under the law of any nation. According to strict constitutional logic, then, a “war on terrorism” is an existential impossibility—if only because “terrorism” is a set of typically para-military tactics, not a country or even a political ideology; and because terrorists do not constitute one or more independent nations, but outside the context of international war, are at most mere bands of private criminals. (footnote 2)
Not surprisingly, Congress has never attempted to exercise its constitutional power “[t]o declare War” (footnote 3) to declare a general “war on terrorism”—because even contemporary Congressman instinctively realize that such a putative declaration would be constitutionally impossible. To be sure, if Congress could satisfactorily delimit the particulars of “international terrorism”, it could outlaw such crime pursuant to its power “[t]o define and punish Piracies and Felonies committed on the high Seas, and Offenses against the Law of Nations”. (footnote 4) But that power is constitutionally separate and distinct from, and independent of, the Congressional power “[t]o declare War”.
Sir William Blackstone was America’s Founding Fathers’ preeminent mentor on the pre-constitutional laws of England (footnote 5), Rather than give his own idiosyncratic notion of “War”, Blackstone’s understanding had long been commonplace among exposition of the Law of nations. (footnote 6)