“Imminence” in the Legal Adviser’s Speech

Ashley Deeks
Wednesday, April 6, 2016, 7:00 AM

Following in an important tradition of speech-giving by senior Obama Administration officials about international law and the use of force, Brian Egan, the new Legal Adviser at the State Department, gave a speech at last week’s Annual Meeting of the American Society of International Law. Egan’s talk, entitled “International Law, Legal Diplomacy, and the Counter-ISIL Campaign,” sought to clarify the U.S. approach to international legal issues that have arisen in the counter-ISIL conflict.

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Following in an important tradition of speech-giving by senior Obama Administration officials about international law and the use of force, Brian Egan, the new Legal Adviser at the State Department, gave a speech at last week’s Annual Meeting of the American Society of International Law. Egan’s talk, entitled “International Law, Legal Diplomacy, and the Counter-ISIL Campaign,” sought to clarify the U.S. approach to international legal issues that have arisen in the counter-ISIL conflict. These included questions related to self-defense, consent to the use of force, the “unwilling or unable” test, customary rules applicable to targeting in non-international armed conflicts, and the meaning of “areas of active hostilities” in the Presidential Policy Guidance on operations against terrorist targets. The U.S. government should be commended for continuing to talk about these issues, providing clarifications, and adding nuance to existing explanations of its legal theories.

There has been limited reaction to the Legal Adviser’s speech, though Marty Lederman has a comprehensive post on the speech here. The Legal Adviser himself forecast this when he noted early in his speech that he suspected and hoped that much of what he said would not be surprising. At least one point from the speech, however, is worth drawing out: Egan’s discussion of “imminence” in the jus ad bellum context.

The concept of imminence assumes relevance in the context of anticipatory self-defense. When is a threat of an armed attack by a non-state actor imminent enough to trigger the right of the victim-state-to-be to respond forcibly in self-defense? The United States has come under fire from some corners for asserting that states today should embrace a more capacious concept of imminence when assessing threats by non-state terrorist groups. A heated debate arose when the Bush Administration first proffered this basic idea in its 2002 National Security Strategy, which it framed as a need to expand the concept of anticipatory self-defense in a world filled with terrorist actors and the proliferation of weapons of mass destruction. The Strategy stated, “If necessary, however, under long-standing principles of self-defense, we do not rule out the use of force before attacks occur, even if uncertainty remains as to the time and place of the enemy’s attack. When the consequences of an attack with WMD are potentially so devastating, we cannot afford to stand idly by as grave dangers materialize. This is the principle and logic of pre-emption.”

Though the Obama Administration has not argued in support of pre-emptive self-defense, which effectively de-couples the right of self-defense from the need to show some type of imminent threat, the Obama Administration has embraced the need to expand the concept of imminence in the more widely accepted context of anticipatory self-defense—that is, where the actor in question has not yet engaged in an armed attack, but has the capability to do so and is planning such attacks. For example, in John Brennan’s speech at Harvard Law School in 2011, he stated:

[A]n increasing number of our international counterterrorism partners have begun to recognize that the traditional conception of what constitutes an “imminent” attack should be broadened in light of the modern-day capabilities, techniques, and technological innovations of terrorist organizations.

Many observers have questioned this notion of “imminence,” arguing that the traditional exercise of self-defense, incorporated in Article 51, has required that the need to act must be—in the words of the famous Caroline case—“instant, overwhelming, and leaving no choice of means, and no moment for deliberation.” Egan’s speech seems to represent an effort to respond to some of these critiques. Specifically, he fleshes out factors that the United States deems relevant in assessing when an armed attack is imminent. The factors are drawn directly from those Daniel Bethlehem proposed in a 2012 AJIL piece. Bethlehem, in turn, noted that the principles in his piece were “informed by detailed discussions over recent years with foreign ministry, defense ministry, and military legal advisers from a number of states who have operational experience in these matters.” Those factors include

the nature and immediacy of the threat; the probability of an attack; whether the anticipated attack is part of a concerted pattern of continuing armed activity; the likely scale of the attack and the injury, loss, or damage likely to result therefrom in the absence of mitigating action; and the likelihood that there will be other opportunities to undertake effective action in self-defense that may be expected to cause less serious collateral injury, loss, or damage. The absence of specific evidence of where an attack will take place or of the precise nature of an attack does not preclude a conclusion that an armed attack is imminent for purposes of the exercise of the right of self-defense, provided that there is a reasonable and objective basis for concluding that an armed attack is imminent.

This explication of relevant factors—not just by a prominent former governmental official in his personal capacity but now by a state itself—is an important instance of state practice and ultimately may contribute to the development of customary international law more generally. This arguably could affect the scope of the article 51 exception for “inherent” self-defense (although it is contested whether future developments in custom can expand what article 51 exempts).

It also is a familiar move in the jus ad bellum. I recently wrote a paper, titled “Multi-Part Tests in the Jus Ad Bellum,” that explores when and why states and scholars advert to multi-part tests in this area of international law.

At various times since 1945, states have sought to use force in situations not expressly contemplated by the Charter’s text. Those who view the Charter as a “living instrument” urge flexibility in interpretation when approaching these nonstandard cases. At the same time, they recognize that permitting excessive flexibility will destabilize the Charter. As a result, some states and scholars promote “constrained flexibility” by proposing multi-part tests (MPTs) to guide state decision-making in these nontraditional cases. The MPTs propound on the meaning of sparse texts (i.e., the Charter and the basic customary rules of necessity and proportionality) by articulating specific, legalistic elements or factors against which states may evaluate their contemplated actions. When states themselves author MPTs, the authoring state signals to other states how it will analyze its own uses of force in that context and, implicitly, those of other states. MPTs thus offer an opportunity for law specification and law development.

That is basically what is happening in the Egan speech. In the wake of threats by non-state actors that, in the U.S. view, demand the use of force but don’t fit squarely into the literal text of article 51, the United States has proposed something roughly akin to a multi-part test to structure and defend its uses of force in anticipatory self-defense while preserving the relevance of the U.N. Charter. The proposed factors will—at least to a modest extent—constrain U.S. actions taken in anticipatory self-defense and also signal to similarly-situated states how the United States expects those other states to evaluate the situation.

Will Egan’s factors be well-received? My piece argues as a predictive matter that an MPT will garner more support when (1) it is rule‑like and (2) it closely tracks the underlying Charter or customary rule on which the MPT expounds. The more the MPT shifts toward a “necessary elements” format, the more easily it can combat the most potent critique of MPTs: their excessively discretionary nature. In this case, the U.S. government’s set of imminence-related factors is not particularly rule-like, and thus other states and commentators may view the MPT as doing insufficient work to constrain the present and future actions of the state that proposed it. As to the second prong, the imminence concept is linked to the customary rule of necessity, because it helps to explicate when a use of force in self-defense is necessary. The U.S. government factors relating to the probability of attack and concerted pattern of armed activity also find a pedigree in the facts of the Caroline case. The factors thus seem like an important start to what is likely to be a long conversation.

MPTs have their detractors, to be sure. In general, one’s perception of the utility of MPTs will be driven by one’s view of how much guidance the Charter’s text and customary jus ad bellum rules already provide and how completely they cover the landscape. But we don’t live in a first-best world in which the P-5 always agree to act in the face of a particular situation that threatens the peace. Nor do we live in a second-best world in which states are prepared to amend the Charter to clarify the meaning and permissible applications of article 51 and the customary rules of necessity and proportionality. Thus, my paper concludes, “For those who think that the Charter contains a fair amount of ambiguity and must evolve, at least modestly, to keep pace with modern developments, MPTs may serve as focal points, self‑constraints, and conflict‑minimizing tools—perhaps the best we have as long as we live in this third‑best world.”

Ashley Deeks is the Class of 1948 Professor of Scholarly Research in Law at the University of Virginia Law School and a Faculty Senior Fellow at the Miller Center. She serves on the State Department’s Advisory Committee on International Law. In 2021-22 she worked as the Deputy Legal Advisor at the National Security Council. She graduated from the University of Chicago Law School and clerked on the Third Circuit.

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