As was reported in the New York Times and elsewhere on May 2, the U.S. fired at least four Tomahawk cruise missiles into Somalia, striking a compound in the town of Dusa Marreb, killing at least ten people. 
One of them, the primary target of the attack, was an alleged Al Qaeda operative named Aden Hashi Ayro, who was suspected of having killed a BBC journalist among other things. He was reported to be a notorious terrorist.
Several blog posts have noted the lack of mainstream discussion on the legality of this missile strike. Prof. Marty Lederman, writing in Slate, suggested that few seem to care whether it was legal. But even among the bloggers, the majority of posts I have seen, as in the case of Prof. Lederman’s, have focused primarily on the constitutional issues of whether the President had sufficient authority, explicit or otherwise, to launch such attacks. There has been some discussion of the jus in bello issues, such as whether the strikes met the criteria of military necessity and proportionality, given the apparent collateral damage. But few have addressed the jus ad bellum issues – was this missile strike, and those prior to it (there have been several such attacks on Somalia since 2006) lawful under the international laws on the use of armed force?
Developments in jus ad bellum?
Prof. Jullian Ku was one of few that has raised the issue, on Opinio Juris, but he merely floated the idea that since such strikes have met with little objection, they may be evidence that the U.S. is operating in a legal paradigm that approximates that of war. Implicit in this is the proposition that there have been developments in international law on the use of force since 9/11 that permit one to wage war on organizations, and which give the global “war on terror” a legal foundation that would permit such strikes against Al Qaeda operatives at large in a “failed state”.
As I commented on his post over at Opinio Juris, I question whether the fact that there has been little formal objection to the strike can be said to support the inference that the strikes were therefore lawful or justifiable under international law, or that it reflects developments in international law that permit such strikes.
The prohibition on the use of force
Under the traditional understanding of jus ad bellum the strikes would appear to constitute a use of force in violation of Art. 2(4) of the U.N. Charter, which prohibits states from using force against the territorial integrity or political independence of a state, or in any other manner that is inconsistent with the purposes of the U.N.
Prof. Lederman questioned whether the strikes might fall outside of the scope of this prohibition, given that it was not really aimed at Somalia per se, but rather at terrorists operating within Somalia. It seems very unlikely that this distinction could negate the application of Art. 2(4). If Mexico fired missiles into Texas to take out some alleged narco-terrorists there, the U.S. would no doubt rightly perceive it to be a violation of its territorial integrity and an armed attack in violation of its sovereignty, inconsistent with the purposes of the U.N.
The right to self-defence
In interpreting Art. 2(4), one also needs to consider the operation of Art. 51 of the U.N. Charter, which provides that member states have an inherent right to exercise individual or collective self-defence in the event of an armed attack. Missile strikes aimed at targets within one’s territory would most certainly constitute such an armed attack and provide a state with the legal justification of responding with force in self-defence.
The missile strikes on Somalia would constitute such armed attacks justifying the right to the exercise of self-defence, and the fact that Somalia is in a state of political disarray, and able neither to effectively object or to mount any sort of self-defence, does not alter the legal analysis. That in turn informs the question of whether such armed attacks, which would justify self-defence, constitute an unlawful use of force in violation of Art. 2(4).
Continued exercise of self-defence?
Of course, attacks that are themselves conducted as part of the exercise of self-defence cannot constitute unlawful acts of aggression. Can it be said that the strikes on Somalia are part of a continued American exercise of the right of self-defence as against Al Qaeda in response to the 9/11 attacks? This brings one back to the issue of whether international law recognizes armed conflict at large against non-state terrorist organizations.
The U.S. invasion of Afghanistan was based on the Art. 51 right of self-defence, but was understood to be against the state of Afghanistan for its harbouring of the terrorists who conducted the attack. Notwithstanding the continued inusurgency in Afghanistan today, the initial invasion and occupation of Afghanistan ended years ago. Has there been some development of international law that permits states to employ military force rising to the level of armed attacks against third states on the basis that enemies from a former conflict have now taken refuge there?
The war on terror and jus ad bellum
The constant refrain that the U.S. is engaged in a so-called “war on terror” does not advance the analysis. An effort against terrorism in and of itself does not come within the definitions of international armed conflict in international law, nor do many aspects of that effort trigger the application of the laws of war. What is hte legal development that provides a legal justification for military strikes on countries in which the operative of an organization defined as “the enemny” may be residing at any given time?
A hypothetical may help us draw the distinction between the so-called criminal law paradigm and laws-of-war paradigm into stark relief. Consider a case where an alleged Al Qaeda operative is found to be residing in Canada. The U.S. requests of the Canadian government that he be apprehended. The Canadian government, however, approaching the issue from the criminal law paradigm, advises Washington that it has insufficient evidence to apprehend or detain him under the criminal laws of Canada (which now include a number of enhanced terrorism-targeting provisions). May the U.S., under the cloak of the war-paradigm of the so-called “war on terror”, and with assertions that Canada is now “harbouring terrorists”, fire cruise missiles into the apartment building where the Al Qaeda operative is holed up?
For those who argue that the “war on terror” is really an activity to which the laws of war apply, and that international law with respect to jus ad bellum has somehow changed since 9/11, the burden is on them to actually describe how, precisely, that is so.
This is not to say that the strikes were unlawful, but rather to emphasize that the questions raised by strikes such as those on Somalia certainly require much greater study and discussion. Their lawfulness ought not to be presumed. The foregoing review merely scratches the surface of the issues, and the questions should be getting more attention in both the mainstream media and in the academy.