For an audio version of this essay read by the author, please click here.

This essay first appeared in the Jan. 10, 2024 Epoch Times.

Part I and Part II in this series explained that:

• The Constitution grants the federal government the exclusive power to wage offensive war; but
• the states as well as the federal government may wage defensive war;
• the states may wage defensive war against insurrectionists and against actual or threatened invasions—including invasions by those international criminal gangs the Founders called “enemies of the human race;” and
• the historical record shows that the mass illegal immigration at the Southern border is an “Invasion” as the Constitution uses that word.

A Not-So-Hypothetical Situation

As part of our research into state war powers, my co-author, Andrew T. Hyman, and I examined the scope of “defensive war” as the Founders understood it. In other words, we examined what an American state can, and can’t do, when fighting a defensive war.

To make it easier to understand what we learned, let’s use the following not-so-hypothetical illustration:

“Texas state authorities determine that their state is being invaded from Mexico. They further find that the invasion is being promoted by organizations determined to flood the U.S. with undocumented migrants and by international criminal gangs trafficking in drugs and people.

“Texas authorities also determine that the Mexican government cannot prevent the invasion, because 30 to 35 percent of Mexican territory is “ungoverned space,” where criminal cartels operate freely (pdf).”

Now, in this situation, the Constitution forbids Texas from waging offensive war. Only the federal government may do that. Thus, Texas may not attack Mexico purely for revenge, deterrence, or compensation. Nor may Texas drop bombs on Mexican cities or scour the seas to sink Mexican ships.

In addition, the Constitution specifically rules out state use of “letters of marque and reprisal” (Article I, Section 10, Clause 1). These are documents commissioning private ships to ply the waters in search of enemy craft and, finding them, capture them or send them to the bottom. Even if the Constitution did not prevent states from using letters of marque and reprisal, international law would: They were effectively abolished by an international agreement signed in 1856.

But that doesn’t mean Texas must sit back and “let the feds handle it” (or mishandle it). On the contrary, an invasion of a state empowers—and obligates—that state’s government to do what is legal and reasonably necessary to stop the invasion.

Under the Constitution, the fact of invasion empowers the state to raise an army, either through volunteers or by conscription, for the purpose of repelling the attack. The Constitution does not require this army to be part of the formal militia.

A state may take defensive measures associated with war but falling short of full-blown hostilities. Some of these defensive measures are discussed in the next installment. One example is that the state may build protective barriers. However, as also discussed in the next installment, some of these measures may conflict with federal law or policy.

Moreover, the state invaded has the right to seek out and kill the invaders and those responsible for the invasion. As noted by Emer de Vattel, the Founders’ favorite international law scholar:

“The enemy attacking me unjustly, gives me an undoubted right of repelling his violences [sic]; and he who opposes me in arms, when I demand only my right, becomes himself the real aggressor by his unjust resistance . . . For if the effects of this force proceed so far as to take away his life, he owes the misfortune to himself; for if by sparing him I should submit to the injury, the good would soon become the prey of the wicked. Hence the right of killing enemies in a just war is derived; when their resistance cannot be suppressed, when they are not to be reduced by milder methods, there is a right of taking away their life . . . But the very manner by which the right of killing enemies is proved, points out also the limits of this right. On an enemy’s submitting and delivering up his arms, we cannot with justice take away his life.”

In addition to killing enemies who refuse to surrender their arms, a state under invasion may seek out hostile forces in their territory or in the state’s own territory. This means that if Mexico does not stem the invasion, Texas may make forays across the border to attack those masterminding the assault. Besides killing invaders (if necessary), Texas may capture them, seize their property, and remove them to, and hold them in, any safe location. The state also may punish—even execute—those guilty of war crimes.

Finally, if consistent with state law, Texas may prosecute for treason any of its own citizens caught assisting the enemy. (Texas Constitution, Article I, Section 22).

If those tactics sound extreme, they are. War—even defensive war—is extreme.

Two “Yes, buts. . .”

I hasten to qualify the foregoing in two ways.

First, merely because the Constitution permits a course of action does not mean that an invaded state should pursue it. Most of the illegal migrants are civilians seeking a better life. They should be deported, not mistreated. States should limit the use of deadly force to the invasion’s organizers and, if necessary, to any captives who refuse to comply with reasonable orders, including orders of removal.

Second: There are various state actions traditionally associated with war that the federal government may not override. But there are other actions that are subject to federal “preemption.” The next installment in this series will address this difficult issue.