For an audio version of this essay read by the author, please click here.
This essay first appeared in the Jan. 9, 2024 Epoch Times.
Part I of this series showed that under the Constitution, an “invasion” triggers powers and obligations for both federal and state governments. It also showed that mass unauthorized immigration at the Southern border meets the constitutional definition of an “invasion.”
This Part II explains federal and state responsibility in the face of invasion. Further, this Part introduces the topic of trans-national criminal gangs, and how states may respond to them.
All the installments in this series are based on a research article I co-wrote with legal scholar Andrew T. Hyman (pdf).
Some Basic Principles
War, borders, and foreign affairs are subjects of international law. The American Founders called international law the “law of nations.” For their background in the law of nations, the Founders relied on their own experience and on a handful of leading authors: the Dutch writer Hugo Grotius, the Swiss scholar Emer de Vattel, and others (pdf). Reading those authors today sheds light on the Constitution’s meaning and organization.
Founding-era “law of nations” books distinguished between offensive wars and defensive wars. A sovereign fought a just offensive war to seek compensation for injury or to deter an enemy from inflicting injury. (Wars for mere conquest were considered “unjust.”) A sovereign launching a just offensive war generally preceded it with a formal announcement called a declaration of war.
Sovereigns fought defensive wars to prevent injury. Examples were military responses to invasion and insurrection. Usually a sovereign engaged in a defensive war was not the first to strike. But if an invasion was imminent, a sovereign could launch a pre-emptive attack, and it still was considered defensive.
A sovereign commencing defensive military operations was not required to issue a declaration of war, although it might do so.
Federal War Powers
The division between offensive and defensive warfare is baked into our Constitution. The division helps explain which military powers the Constitution granted the federal government and which military powers the states retained.
Under the Constitution, only the federal government may wage offensive war. Congress, therefore, may “declare War” (Article I, Section 8, Clause 11).
The Constitution also grants the federal government power to wage defensive war. Article II, Section 3 directs the President to “take Care that the Laws be faithfully executed.” This was the section that gave Abraham Lincoln authority to commence military operations against the seceding Southern states.
Article IV, Section 4 says that “The United States shall . . . protect each [state] against Invasion; and on Application of the Legislature, or of the Executive (when the Legislature cannot be convened) against domestic Violence.” This language means (1) the federal government is empowered—and required—to wage defensive war against invasion (a duty the Biden administration is disregarding), and (2) the federal government is empowered—and required—to wage war or undertake a police action against domestic violence, if an affected state demands that it do so.
Several other constitutional provisions give the federal government authority to create a war machine: raising armies, maintaining a navy, calling forth state militias, and so forth. In all cases, the President is the commander in chief of the armed forces (Article II, Section 2, Clause 1).
State War Powers
The Constitution did not transfer all sovereignty to the federal government. Some sovereignty—including some sovereign war powers—remained in the states. During the constitutional debates of 1787-1790, the Constitution’s advocates repeatedly explained this. State war power did not derive from the Constitution. It was part of the reservoir of sovereign authority retained by the states (“reserved”) after the document was ratified.
Article I, Section 10, Clause 3 limited these reserved state war powers, but also recognized them:
“No State shall, without the Consent of Congress . . . keep Troops, or Ships of War in time of Peace . . . or engage in War, unless actually invaded, or in such imminent Danger as will not admit of delay.”
Let’s flip that language to an affirmative form:
“Any state may keep troops and ships of war in time of war, . . . and engage in war . . . if actually invaded or in such imminent Danger as will not admit of delay.”
In other words, states may wage defensive, but not offensive, war. Unlike the Articles of Confederation (1781-1789), the Constitution imposed no limit on the armies or navies a state may raise during a time of war. (The states are not limited to their militias.) Unlike the Articles, the Constitution laid down no requirement that the war be congressionally-declared and no restriction on the nature of the invasion. The only requirements imposed by the Constitution are that there be an actual invasion or an “imminent Danger” of one.
It is common to say that the Constitution reduced state power from what it had been under the Articles of Confederation. But this was not true in the area of warmaking.
Another point about the states’ reserved powers: The Constitution did not abolish state capacity to enforce the law against criminals. Which brings us to the next topic.
“Enemies of the Human Race”
During the 18th century, civilized nations often were disturbed by criminal gangs that recognized no sovereigns. Legal writers called these gangs, hostes humani generis— a Latin phrase meaning “enemies of the human race.”
Enemies of the human race might operate on the sea, prey on shipping, and attack port towns. If so, they were called “pirates.” But enemies of the human race also included land-based gangs of thieves, deserters, poisoners, assassins, incendiaries, and (as the legal commentator William Blackstone characterized them) “unauthorized voluntiers [sic] in violence.”
The Constitution left the states with power to conduct war against invasions launched by enemies of the human race. It also left the states with police power to respond to their criminal acts.
The attitudes of the founding generation against these malefactors was remorseless. As Emer de Vattel, the Founders’ favorite international law authority, wrote:
“[I]f the justice of each nation ought in general to be confined to the punishment of crimes committed in its own territories; we ought to except from this rule, the villains, who by the quality and habitual frequency of their crimes, violate all public security, and declare themselves the enemies of the human race. Poisoners, assassins, and incendiaries by profession, may be exterminated wherever they are seized . . . .”
Can you think of some “enemies of the human race” operating along our Southern border today?