In the aftermath of the horrific terrorist attacks in Brussels, and amid reports that ISIL has not only claimed responsibility for the attacks, but has also trained “400 fighters to attack Europe in wave of bloodshed,” it is appropriate to examine Elvina Pothelet’s provocative piece assessing the legality of targeting individuals in ISIL training camps, particularly those who are being trained to engage in attacks in Europe at some indeterminate future date. “Provocative” of course, does not necessarily mean that every interpretation of her piece will inevitably lead to the right legal conclusions. Let’s examine the issues her essay raises with a view towards understanding their implications for international law writ large.

Pothelet points to an ambiguous statement by the French Defense Minister that could be read to indicate France has sufficient intelligence to distinguish between individuals being trained for combat in Iraq and Syria and those who will be sent to Europe to mount terrorist attacks. After saying the former group can almost certainly be lawfully targeted, she goes on to discuss whether ISIL trainees who being prepared “to mount terrorist attacks in Europe” remain civilians for the purpose of the law of armed conflict. In the end, she indicates that they may not be targetable absent a further showing that they are “directly participating in hostilities” (a principle drawn from the language of Additional Protocol I to the Geneva Conventions).

How does Pothelet come to this conclusion? In her opinion, “the degree of remoteness and uncertainty between the training of IS fighters and the potential attacks in Europe is generally too significant for the training alone to qualify as direct participation in hostilities.” She questions, for example, whether training for a one-time suicide mission is enough “continuous combat” to change someone’s status from protected civilian to targetable belligerent.

In fairness to Pothelet, she seems to be basing her view on the International Committee of the Red Cross’ (ICRC) interpretation of what kinds of activities would cause someone to lose the protection of civilian status. The ICRC finds that switch occurs once someone assumes a “continuous combat function” in an organized armed group. Although the ICRC says this can be established by “any preparations and geographical deployments or withdrawals constituting an integral part of a specific hostile act,” it seems that Pothelet would not find general preparations for attacks against Europe specific enough to meet this bar, despite ISIL’s “success” in Paris (and now Brussels).

Perhaps more importantly, the ICRC’s view as to the ability of individuals to move in and out of “continuous combat function” is contentious. For example, Michael Schmitt rather thoroughly deconstructed the concept in a 2010 article, and I believe his arguments have since been supported by state practice. In this instance (as illustrated below), there does not seem to be any state practice to establish or reinforce a norm that would require any distinction between ISIL trainees in a training camp based on their future objectives.

In any event, as Pothelet points out, the Global Coalition to Counter ISIL (a 65-nation consortium in which the parties have agreed to conduct or support military operations against ISIL) regularly reports on the targeting of ISIL training camps. (And you could probably add to Russia, Iran, and Syria to the list of attackers.) Since few war crimes are as serious as the direct and systematic targeting of civilians, it is important to take the issue she raises about the trainees’ statuses seriously.

That said, the better view is that once an individual deliberately joins what is known to be an organized armed group (one that is indisputably engaged in continuous combat operations as part of an armed conflict), and then undergoes training for hostile acts, that person is no longer a civilian for targeting purposes until he unmistakably ends his relationship with the group (and he is responsible for making such termination manifest to a reasonable attacker). In other words, the focus of the inquiry should be on whether the armed group meets the standard of continuous combat function, not the near-impossible task of attempting to discover the individual combat records and intentions of each trainee aiming to commit hostile acts of some sort.

I am firmly convinced that ISIL trainees — preparing for attacks in Europe or anywhere else — are, like other members of ISIL, subject to “status-based” targeting on the same basis as a member of a traditional armed force. As Hays Parks put it, members of an armed force “are liable to attack at any time or place, regardless of their activity when attacked … [and their] vulnerability to lawful targeting … is not dependent upon his or her military duties, or proximity to combat as such.” It is wholly unrealistic to expect that those nations who want to attack the ISIL threat at its source must somehow discern the intentions of individual trainees as to the kind and extent of the hostile acts they intend to carry out.

Putting aside the sheer impracticality of making such a determination among trainees in an enemy camp, no rule of the law of war requires it. As Pothelet says, it is unlikely that France can draw such a distinction, and even if it could, I maintain that it is not required to by international law. What is more, French President François Hollande stated after the Paris attacks that France is “at war” with ISIL (a sentiment echoed by French Prime Minister Manuel Valls after the Brussels attacks), so it seems likely that France is now relying on a status-based targeting legal theory, even if it didn’t previously.

Furthermore, where is the evidence that ISIL’s military organization and doctrine allows trainees to pick and choose their terrorist activities, with ISIL being bound to give them that assignment? Where is the evidence that even a single “suicide mission” in Europe is not part of a broader ISIL strategy encompassing many other acts of violence that continues even today? In fact, the evidence shows the contrary: Individual acts of terror in Europe and elsewhere have a larger purpose, that is, they are intended to “to create chaos in the wider world” and thereby “incite a global apocalyptic war.”

A legal norm that preserves civilian status for those being trained for only a single act of belligerency despite the larger purpose would have profound implications. Why then should non-state actors be privileged as protected civilians over those serving in conventional militaries simply because they are being trained for a one-time act of belligerency? Is there any logic to the distinction between international armed conflicts and non-international armed conflicts on this issue? Why should members of an armed force training, for example, for a (presumably) one-time nuclear mission be deemed combatants, while we preserve protection for a member of an organized armed group who is training to conduct a suicide mission to set off a nuclear device in Europe or elsewhere?

Wholly apart from “status-based” targeting, we should also consider the separate authority to conduct attacks as a matter of anticipatory self-defense in the face of an imminent threat. Does attacking ISIL trainees meet the “imminence” criteria? Yes, it does — even if you assume (as I do not) that some ISIL trainees are being trained exclusively for a single suicide mission in Europe.

Keep in mind that ISIL terrorists are trained to “blend” into Western populations in Europe and elsewhere. Once that happens, it can be extraordinarily difficult to find them before they commit their acts of violence against vulnerable civilians, and this terrorist methodology is one reason why the modern meaning of imminence has evolved. A good statement of the contemporary view of the norm is reflected in the Tallinn Manual’s discussion of imminence. It points out that a majority of international experts consulted for the project concluded that a “kinetic or cyber” act in anticipatory self-defense may be taken at the “last feasible window of opportunity.” The Manual adds:

This window may present itself immediately before the attack in question, or, in some cases long before it occurs. The critical question is not the temporal proximity of the anticipatory defensive action to the prospective attack, but whether a failure to act at that moment would reasonably be expected to result in the State being unable to defend itself effectively when the attack actually starts. (Emphasis added.)

True, the Tallinn Manual focuses on cyber war, but in this respect, its reference to “kinetic” acts illustrates the implications of 20th century threats which can permit relatively small numbers of belligerents to leverage technology to inflict significant civilian casualties. It is eminently reasonable for a nation, and especially one that seeks to balance security with civil liberties for its citizenry, to conclude that its “last feasible opportunity” to effectively defend itself against a terrorist attack is to strike the terrorists as they are being trained to commit their mayhem, and “long before” they have the opportunity to burrow into the civilian population and hide themselves. Thus, there are two separate but strong legal bases to target ISIL trainees.

Furthermore, Pothelet’s discussion does not grapple with the ongoing practices of the more than five dozen nations composing the Global Coalition to Counter ISIL. As a matter of international law, the actions of “specially-affected states” — in this instance those states with a great “extent and depth of experience” in actual military operations — are significant in interpreting the meaning of international law.

It’s hard to imagine, especially after Brussels, that any nation’s leader would demand the level of detail about individual ISIL militants that Pothelet discusses. Most leaders, I believe, accept at face value the group’s own assertions about their quest for global domination and would recognize the threat that training for attacks pose for practically every nation on the planet. I simply do not think that international law can sustain its credibility if it holds that — despite the recent attacks in Europe and elsewhere that local law enforcement efforts have proven inadequate to prevent — it is nevertheless unlawful to use military force to strike known ISIL trainees absent some sort of explicit evidence about their individual preparation for a yet-to-be-determined number of near-term acts of terrorism that would satisfy a contentious interpretation of “continuous combat function.” Of course, the facts do matter, and in situations involving persons other than ISIL members may produce a different analysis, but at least as to ISIL trainees, it is clear that they are lawfully targetable.

It is rather ironic that shortly after Pothelet’s piece appeared, the US conducted airstrikes against an al-Shabaab training camp in Somalia that killed at least 150 trainees and others, and later conducted a “massive” airstrike on a terrorist training camp in Yemen, neither generating claims of civilian casualties. No one remotely insinuated that the individual trainees had to be queried as to which acts of terror they intended to inflict before the attack that killed them. It is simply unthinkable that nations would allow a norm to arise that would prohibit attacks against those training to commit the kind of vicious and barbaric acts against the helpless that so defines al-Shabaab and other contemporary terrorists.

As I’ve said before, academics can make a very real contribution to the dialogue in the development of the law of war. In this instance, Pothelet has done a great service by raising the proverbial red flag about problematic assertions by government officials, and how they could be interpreted in the legal context. For that she deserves kudos for stimulating the kind of dialogue that advances our understanding of the law.