No, There Is No International Legal Basis for the “Bloody Nose” Strategy

In the end, customary practice suggests that, subject to the necessity and proportionality criteria, even small-scale bombings, artillery, naval or aerial attacks qualify as ‘armed attacks’ activating Article 51 UN Charter, as long as they result in, or are capable of resulting in destruction of property or loss of lives. By contrast, the firing of a single missile into some uninhabited wasteland as a mere display of force, in contravention of Article 2(4) UN Charter, would arguably not reach the gravity threshold.

The attack that the authors imagine — an unarmed missile fired into Japan’s territorial sea — is precisely the kind of attack that is not “capable of resulting in destruction of property or loss of lives.” That attack thus cannot give rise to the right of self-defense. Indeed, even the source that the authors cite, Karl Zemanek’s entry “Armed Attack” in the Max Planck Encyclopedia of International Law, rejects their insistence that an unarmed missile fired into Japan’s territorial sea could “reasonably be interpreted as an armed attack.” Here is what Zemanek says about de minimis attacks (emphasis mine):

In sum, it is submitted that regardless of the dispute over degrees in the use of force, or over the quantifiability of victims and damage, or over harmful intentions, an armed attack even when it consists of a single incident, which leads to a considerable loss of life and extensive destruction of property, is of sufficient gravity to be considered an ‘armed attack’ in the sense of Art. 51 UN Charter.

The authors’ claim that the US would be entitled to act in “collective self-defense” in response to an “armed attack” in the form of an unarmed missile fired into Japan’s territorial waters is also problematic. Here is their argument:

The 1960 Treaty of Mutual Cooperation and Security between the United States and Japan states “[e]ach Party recognizes that an armed attack against either Party in the territories under the administration of Japan would be dangerous to its own peace and safety and declares that it would act to meet the common danger in accordance with its constitutional provisions and processes.” This treaty may provide a basis for the United States’ to engage in a limited retaliatory strike. One could argue that, pursuant to the 1986 Nicaragua case out of the International Court of Justice (ICJ), the United States would have to obtain Japan’s affirmative consent before engaging in a strike against North Korea in collective self-defense. However, Article 51 certainly does not refer to any such prerequisite, and the ICJ’s conclusion in Nicaragua is highly debatable. On a more practical note, it is highly unlikely Japan would oppose a collective self-defense strike by the United States.

It is not clear why the authors believe that Japan would not need need to specifically consent to “collective self-defense.” There are two possible interpretations of their argument: (1) the Treaty of Mutual Cooperation automatically provides the US with the consent it needs to “defend” Japan in case of an armed attack; (2) collective self-defense never requires the consent of the attacked state. The authors’ criticism of the Nicaragua judgment implies that they take position (2). As Ruys explains, however, state practice — from Jordan in 1958 to South Vietnam in 1965 to the Soviet invasion of Afghanistan in 1980 — indicates that collective self-defense is lawful only when the state with the right of individual self-defense requests it (pp. 88-89):

This brings us to the third and decisive reason why the conception of collective ‘defence of the other’, endorsed by the ICJ and a majority of legal scholars, holds the upper hand over the ‘defence of the self’ approach: customary practice provides virtually no support either for the requirement that a proximity relationship should exist, or for the idea that collective self-defence may be exercised absent the approval of the actual victim State. On the contrary, practice convincingly shows that a State which is the subject of an attack has a legal right to ask for military assistance.

[snip]

In sum, in each case, what was deemed crucial was whether the actual victim State had a right of individual self-defence, and whether it approved of the actions of the assisting State. Of course, the assisting State will most often have some sort of interest in responding to the victim’s request; States seldom engage in military action out of pure altruism. Yet, practice makes clear that a proximate relationship is not a legal criterion; only the victim State’s approval is.

The stronger argument, then, is that the Treaty of Mutual Cooperation would automatically provide the necessary consent for US to engage in “collective self-defense.” Aurel Sari raised this possibility on Twitter last night. I am not convinced that the Treaty eliminates the need for Japan’s consent to armed force being used on its behalf. In particular, Art. IV provides that “[t]he Parties will consult together… at the request of either Party, whenever the security of Japan or international peace and security in the Far East is threatened,” which seems to contemplate acts of self-defense being undertaken only with the specific agreement of both Japan and the US. But Aurel’s argument must still be taken seriously, and it provides the only coherent basis for the authors’ position on collective self-defense.

(As an aside, I find very unconvincing the author’s casual assertion that “it is highly unlikely Japan would oppose a collective self-defense strike by the United States.” On the contrary, I think Japan would be quite likely to oppose the US responding to a unarmed missile attack by using force — even relatively restrained force — directly against North Korea. A North Korean response would be more likely to target Japan than the US. So Japan would have every incentive not to consent to “collective self-defense” in such a situation.)

Finally, I find very unconvincing the author’s insistence that the US is close to having an individual right of self-defense against North Korea:

Even without another missile targeting Japan, the United States could arguably rely on its own Article 51 individual right of self-defense to justify a “bloody nose” strike. While somewhat controversial, the United States interprets the individual right of self-defense to allow for a preemptive-but-proportional strike when the need to do so is imminent. In other words, if the United States determines North Korea’s behavior indicates a forthcoming attack it can act in self-defense before absorbing the first blow.

North Korea’s recent activities help support a preemptive self-defense argument. Despite extensive efforts by the international community, including through diplomacy, negotiations, collaboration, and sanctions, North Korea continues to defiantly test powerful nuclear weapons and launch ballistic missiles. Furthermore, it has gone to great lengths to conceal its nuclear testing program by creating underground facilities and intricate tunnel systems. This behavior, coupled with North Korea’s pattern of aggressive rhetoric and threats against the United States and other nations, makes a preemptive use of force seem more and more necessary. As the North Korean threat increases and non-military measures are exhausted, it becomes reasonable to believe that the last opportunity for the United States to act is fast approaching.

There is no question that the US would have the right to act in self-defense to prevent an imminent attack by North Korea — anticipatory self-defense. But the authors seem to adopt an understanding of self-defence’s necessity requirement that goes well beyond the traditional Caroline standard of imminence, according to which the need to act must be “instant, overwhelming, and leaving no choice of means, and no moment for deliberation.” They specifically argue for preemptive self-defense, a term that the US traditionally uses to describe self-defense against attacks that are not imminent.(The Bush doctrine is an example.) And they invoke the “last opportunity to act” test, which is not necessarily inconsistent with anticipatory self-defense, but can easily be interpreted to allow for preemptive self-defense, as Adil Haque nicely explains here.

If the authors are endorsing a view of self-defense that does not require an imminent attack, their position is clearly wrong. Here is Ruys again (pp. 336-38):

[T]here can be no doubt that even among States adhering to the “counter-restrictionist” view, support for self-defence against non-imminent threats is virtually non-existent. Apart from the fact that the sponsors of Operation “Iraqi Freedom” avoided this justification, it may be observed that many States, such as Germany, Japan, Switzerland, Uganda, Singapore or Liechtenstein, which professed support for anticipatory self-defence after 2002, nonetheless placed great weight on the imminence requirement. Germany, for instance, expressly denounced an erosion of the Charter framework and State practice via the notion of “preventive self-defence.” Likewise, the French politique de defense unequivocally “rejects… the notion of preventive self-defence.”

What is more, even the “traditional” adherents of the counter-restrictionist interpretation of Article 51 generally appear to uphold the imminence requirement. Despite bold statements by its Prime Minister on the need to adapt the UN Charter, Australia’s response to “In Larger Freedom” was rather cautious: it simply “[supported] reaffirmation by the Secretary-General that Article 51 of the Charter adequately covers the inherent right to self-defence against actual and imminent attack.” Israel called for an explicit recognition in the World Summit Outcome that States may use force in self-defence “in the event of both actual and imminent attacks.” As far as the British position is concerned, Attorney- General Lord Goldsmith in 2004 declared before the House of Lords that: “It is… the Government’s view that international law permits the use of force in self-defence against an imminent attack but does not authorize the use of force to mount a pre-emptive strike against a threat that is more remote.”…

[W]e may therefore conclude that the trend in State practice has been broadly similar to that in legal doctrine: support for anticipatory self-defence has increased, but has by and large restricted this concept to imminent threats.

By contrast, if the authors believe that an imminent attack is required but want to define “imminent” to include the “last opportunity to act” test,” they are not necessarily arguing for an unlawful version of self-defense. It depends on how broadly they interpret “last opportunity to act.” An acceptably narrow definition of the test does, however, seem inconsistent with the authors’ insistence that “[a]s the North Korean threat increases and non-military measures are exhausted, it becomes reasonable to believe that the last opportunity for the United States to act is fast approaching.” To begin with, although there is certainly cause for concern, North Korea does not seem particularly close to having the technology necessary to attack the US mainland with a nuclear missile. Moreover — and more importantly — despite its belligerence and bluster, there is little evidence that North Korea actually wants to attack the US, much less intends to do so as soon as possible. North Korea has long had the ability to launch a conventional attack against numerous US installations overseas — and probably now has the ability to reach the US mainland with a conventional missile. Yet no such attack has ever taken place.

Is it possible that, at some point, the US will have the legal right to attack North Korea in self-defense? Absolutely. But that time is not now — even if North Korea fires another unarmed missile into Japanese territorial waters. And there is little reason to believe that the “last opportunity for the United States to act is fast approaching.” Any argument at present for the “bloody nose” strategy, therefore, is both legally unsound and profoundly counterproductive.