[Note: The following post is derived from remarks prepared for last Friday’s symposium on “Citizenship, Immigration and National Security After 9/11,” sponsored by the Fordham Law Review and the Center on National Security and the Law.]

A common refrain after attempted or successful terrorist attacks by U.S. citizens is that such individuals should be expatriated—that part of the punishment they receive for their misconduct should include revocation of their citizenship. Most recently, we saw this phenomenon in the aftermath of the Boston Marathon bombings, almost as soon as it became clear that one of the two suspects in the attack—Dzokhar Tsarnaev—was a U.S. citizen. And the response to the attempted May 2010 bombing of Times Square by U.S. citizen Faisal Shahzad culminated in the introduction of the Terrorist Expatriation Act (TEA) by bipartisan coalitions in both chambers of Congress—a bill that at least would have attempted to make it far easier to revoke the citizenship of citizens associated with foreign terrorist groups.

In the post that follows, I aim to make three points: First, such proposals utterly misunderstand both the purpose and the legal constraints on expatriation. Second, in light of those considerations, the expatriation of citizens simply because they are “terrorists” is neither necessary nor appropriate. Third, and at a deeper level, debates over expatriation may well simply be standing in, however uncomfortably, for larger debates over whether transnational terrorism is better dealt with through a military or law-enforcement paradigm.

I.  Why Terrorism Doesn’t Fit Into the Existing Expatriation Framework

Except where an American’s citizenship has been obtained through fraud or other illegal activity, the only grounds for revoking citizenship are the seven set forth in section 349(a) of the Immigration and Nationality Act, 8 U.S.C. § 1481(a). I won’t summarize them all here, but as should hopefully be clear from even a brief perusal, the first six typically involve voluntary conduct by the citizen manifesting not animosity toward the United States, but fealty toward a specific foreign sovereign. The seventh ground is somewhat different—authorizing expatriation of citizens convicted of treason, seditious conspiracy, and other offenses of that exceptional nature. In the abstract, then, this might lead some to conclude that expatriation could be based on convictions for other offenses—including, for example, providing material support to designated foreign terrorist organizations (the dominant criminal statute used by the government in post-9/11 terrorism prosecutions).

But in a series of decisions culminating in Vance v. Terrazas in 1980, the Supreme Court has held that the Fifth Amendment’s Due Process Clause requires more. After a series of cases first holding that the government must prove voluntary commission of an expatriating act, Vance reaffirmed that the government must also prove the individual’s specific intent to surrender his U.S. citizenship, as such. (Congress codified Vance in 1986, requiring that all of § 1481(a)’s predicate acts be undertaken “voluntarily . . . with the intention of relinquishing United States nationality.”) In other words, even a treason conviction won’t suffice absent proof that the defendant specifically intended not just to commit treason, but to surrender his citizenship.

This helps to explain why proposals like the Terrorist Expatriation Act have typically been so misguided. For starters, the TEA would have authorized expatriation upon a mere administrative determination by the Secretary of State that a citizen provided material support to a designated foreign terrorist organization. As the Supreme Court held in Kennedy v. Mendoza-Martinez, such expatriation qua punishment requires a criminal conviction—obtained with all of the attendant constitutional safeguards.

But even if proposals conditioned expatriation on a material support conviction, they’d still be fatally flawed; insofar as they would relax the dual voluntariness / intent requirement, they would clearly be unconstitutional. Insofar as they wouldn’t, they’d be pointless; material support is virtually never provided with the specific intent to relinquish citizenship—especially because the material support is not provided to foreign states, but to designated foreign non-state terrorist organizations. Indeed, the material support statute has been so attractive and useful to the government entirely because the government needs to prove so little to obtain a conviction thereunder.

Simply put, there’s probably no way to write a bill like the TEA that would be both effective and constitutional—and so no way in which expatriation is a realistic policy option for legislators grappling with how to effectively deter and respond to the threats posed by transnational terrorism.

II.  Why Expatriation of Terrorists is Neither Necessary nor Appropriate

Putting the legality point aside, though, it bears reflecting on whether such a result is desirable—whether we should prefer a world in which expatriation was a realistic policy option for dealing with citizen terrorists. My own view, perhaps unsurprisingly, is no: That expatriation of terrorists is neither necessary nor appropriate.

On why expatriation is not necessary, consider the purposes of expatriation qua punishment: If it’s incapacitation, the government has plenty of authority that does not categorically turn upon the citizenship of the subject. After all, we have now used lethal force against a U.S. citizen terrorism suspect who we were apparently unable to capture; we have subjected at least two U.S. citizen terrorism suspects to long-term military detention without trial; we continue to retain the authority to try U.S. citizens who violate the international laws of war before military commissions; and, in any event, we possess the formidable array of counterterrorism tools available to ordinary law enforcement—including the draconian sentencing regime in criminal terrorism cases that has been well-documented by others. The harsh but inescapable reality is that terrorism suspects subject to virtually any of these measures will never need to be expatriated.

But there’s also a philosophical disconnect—expatriation of terrorism suspects also doesn’t seem appropriate inasmuch as fealty to / support of non-state terrorist organizations is not allegiance to a foreign government. And historically, expatriation has almost always been in favor of the citizenship of a foreign state; expatriation in this context could / would often produce statelessness.

Relatedly, as the Supreme Court has strengthened the constitutional protections available to non-citizens lawfully present within the United States, it’s also the case that expatriation would produce fewer and fewer consequences than it would have in the past; an expatriated former-citizen terrorist would no longer be able to vote, and would be subject to removal from the United States, among other consequences. But per the above, neither of those consequences are likely to matter to individuals spending the rest of their lives in federal custody.

III.  The Deeper Lesson from Expatriation Proposals

All of this can and should lead us to wonder why expatriation keeps coming up in broader discussions of counterterrorism policy.

I think the answer to that question is obvious: The central analytical problem posed by transnational terrorism over the past decade has been whether legal regimes should respond primarily through a criminal law paradigm focused on punishment and deterrence, or a military force paradigm focused on preemption. And, as we know, the U.S. approach over the past decade has been an inconsistent combination of the two.

And yet, at the end of the day, expatriation both historically and to the present has been a reflection of—and response to—classical state-state interactions; an idea best suited for international conflicts, if you will, not non-international ones. And so the real lesson expatriation may have for ongoing debates over U.S. counterterrorism policy may be in reaffirming just how incomplete and inadequate the classical military paradigm is in responding to the threats posed by international terrorism—and how critical a nuanced application of ordinary criminal law principles becomes.