There is considerable confusion over the legality under international law of taking military action against groups and targets in Syria.

This has led some governments participating in the coalition against the so-called Islamic State (or ISIS, ISIL, or Da’eesh) to support military action within Iraq but not within Syria.

It should be helpful to clarify the different legal authorities under international law under which military force may be used in Syria.

These break down into three broad categories:

(1) Action againsr ISIL in Syria may be taken in exercise of the right of individual or collective self-defense recognized by Article 51 of the U.N. Charter “in the case of an armed attack”. ISIL has launched and is currently engaged in such an armed attack.

If Iraq issues a request for military assistance in repelling that attack, other states may use force that is necessary and proprtional to defending against the attack.

Collective self-defense is a valid justification for U.S. and allied air strikes and land action against ISIL in Syria.

With respect to Kobane, in particular, given the scale of the attack on Iraq and in response to a request from that country for assistance in collective self-defense, Turkey would be justified under international law in sending ground forces into Syria to attack ISIL forces and to repel the attack on that border city.

(2) The second justification for using military force in Syria, whether against ISIL or the Bashar al-Assad regime itself, would be to halt he commission of war crimes and crimes against humanity on a broad scale, until such time as the U.N. Security Council can take effective action to halt the commission of these crimes.

The justification is somewhat novel under international law, but it is submitted makes eminent good sense if narrowly drafted within the framework of the Security Council’s duty to implement the “responsibility to protect” resolution adopted in 2006.

See

(1) “The U.N. Charter, International Law, and Legal Justifications for Military Intervention in Syria—Obama’s Debacle in Syria — Update #83,” The Trenchant Observer, September 1, 2012.

(2) “Humanitarian Intervention in Syria Without Security Council Authorization—Obama’s Debacle in Syria — Update #24,” The Trenchant Observer, April 8, 2012.

In the case of ISIL, this would be a second legal justification, in addition to that of collective self-defense.

In the case of the al-Assad government, which has not committed an “armed attack” against Iraq, this would constitute the main legal justification for taking military action against Syria.

As set forth in considerable detail in previous articles on the legality of humanitarian intervention in Syria to halt al-Assad’s atrocities, the objective of such military intervention should be to halt the commission of war crimes and crimes against humanity by the al-Assad government, under extraordinary circumstances and then only until the Security Council can take effective action.

Whatever objections Russia may have at one time been prepared to make to such an argument, resting on an overly mechanistic interpretation of Article 2 paragraph 4 of the U.N. Charter, it is hardly now in a position to make in view of its invasions of the Crimea and the eastern Ukraine.

(3) The third category of actions involve taking military action within Syria against jihadist or al-Qaeda related groups which have not been involved in an armed attack against Iraq or, arguably, even the large-scale commission of war crimes or crimes against humanity.

Here, the weakness of the international legal arguments used by the U.S. to justify drone attacks and other uses of force outside the Afghanistan-Pakistan war theater comes fully into view.

The U.S. argument turns essentially on assertions that the war against jihadists is global in nature with the result that the war theater is also global, and that certain interptetations by the U.S. of the laws of war or humanitarian law are (1) valid within the framework of humanitarian law itself; and (2) take precedence over the prohibition of the threat or use of force against the territorial integrity or political indedendence of any state contained in article 2(4) of the U.N. Charter, which is universally recognized as a kind of “super” or mandatory law (jus cogens), from which there can be no derogation.

The legal arguments used to support this third category of military actions within Syria are widely disputed outside the U.S. government, and do not appear to be supported by a wide number and variety of states.

That is why the recent U.S. air attacks on the Khorasan group, an al-Qaeda cell deemed to be particularly dangerous, at the same time the U.S. attacked ISIL targets in Syria, created much confusion, particularly in the absence of a detailed written legal justification for either kind of attack.

What was provided was a letter to the U.N. Security Council justifying the attacks both as collective self-defense and in the case of the attack on the Khorasan group as individual self-defense by the U.S.

The latter justification consisted in the mere statement of a conclusion, and failed to address the three self-defense requirements of immediacy, necessity, and proportionality.

The Trenchant Observer

Comments are invited.