Humanitarian intervention: neither right, nor responsibility, but necessity?

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I’d like to offer a small “think piece” contribution to a bigger debate, in which I try and tease out a question that has troubled me: do we need a positive right of humanitarian intervention? What would happen if we conceded it was prima facie an unlawful use of force, but was legally (not just morally) justifiable or excusable in a particular case? My tentative conclusion is that the defence of necessity might prima facie be available to justify a use of force in an humanitarian intervention but would face some significant problems on close scrutiny.

We’re all by now familiar with a certain account of the development of the idea of humanitarian intervention. Let me offer a stylised version of this narrative, with its inevitable oversimplifications by way of introduction.

On one account humanitarian intervention begins as an idea supported by academics, is then invoked (not always consistently) by a small handful of States in concrete cases from the 1990s onwards, is opposed by the 170 member States of the Group of 77 and has now been at least partially supplanted by the “responsibility to protect” (R2P). Paragraph 139 of the World Summit Outcomes Document, however, would appear to reduce R2P to an agreement that the UN is the only legitimate forum for authorising intervention and that the Security Council should act in cases of humanitarian catastrophe. There is very little sign, though, of UN practice in support of this vision of R2P as a collective, institutional responsibility. On this stylised account, what began as an attempt to modify the positive rules on the use of force and non-intervention appears to have been folded back in to the status quo ante. (Albeit that a caveat might have to be entered regarding interventions endorsed or carried out by regional organisations.)

What has always puzzled me about the debate over forceful humanitarian intervention is that proponents and critics have invariably cast it being either a right or a duty. Are there any obstacles to conceptualising it as a justification or excuse for an otherwise illegal use of force? After all, the “right” of self-defence is easily considered such a “circumstance precluding wrongfulness” (i.e. a defence), and is categorised as such in the ILC Articles on State Responsibility.  

Necessity may be invoked where the act which is otherwise contrary to an international obligation “is the only way for the State to safeguard an essential interest against a grave and imminent peril” (Article 25(1), ILC Articles). A State may plead necessity even where its own interests are not directly threatened; the ILC commentary to Article 25 refers to “a grave danger either to the essential interests of the State or of the international community as a whole”.

It would thus seem possible to plead the necessity of forceful intervention to suppress or prevent violations of obligations erga omnes, including at a minimum genocide and certain grave human rights violations (as in Barcelona Traction, para 34). Limitations circumscribing the defence’s availability are not hard to find. As the ILC Commentary to Article 25 notes (at para 5), the Caroline incident criteria provide a useful test of necessity: circumstances justifying necessity must be “instant, overwhelming, leaving no choice of means, and no moment for deliberation”. Vaughan Lowe has, elsewhere, helpfully suggested that forceful action cannot be necessary before diplomacy has been exhausted.

It strikes me that this approach to humanitarian intervention has one major advantage and a number of significant problems. The advantage is that if humanitarian intervention can be justified by a defence available at general international law, in principle there is no need for proponents to point to prior State practice substantiating a prior right of intervention. The lesser of my two problems is that this would involve a concession that any such intervention was prima facie illegal, which intervening States would likely find politically unpalatable. The more significant problem is the possible argument that “the international obligation in question excludes the possibility of invoking necessity” (Article 25(2), ILC Articles). That is, one may point to statements in the Definition of Aggression and the Friendly Relations Declaration to the effect that no consideration of any kind whatever may justify forceful intervention in another State.

Addressing this objection leads us back to the scope of the underlying prohibition on the use of force, and the old and unproductive debates about the correct interpretation of Article 2(4) of the UN Charter or the search for convincing State practice supporting humanitarian intervention outside institutional arrangements. On any objective head-count of UN members, it is quite clear the majority favour an absolute prohibition on intervention (absent UN authorisation, or perhaps action within regional arrangements).

Nonetheless, my argument might suggest that those States already publicly endorsing anticipatory self-defence based on the Caroline criteria could, completely consistently with this position, invoke a plea of necessity as an alternative justification for humanitarian intervention. This conclusion doesn’t perhaps advance debate a great deal, but I would be grateful to know if anyone has explored this line of thought in more detail.

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Tamás Hoffmann says

May 5, 2009

Dear Douglas,

Just two remarks:

1, You mention that "humanitarian intervention begins as an idea supported by academics, is then invoked (not always consistently) by a small handful of States in concrete cases from the 1990s onwards"

Were there any actual cases apart from the well-known example of Belgium in the 1999 ICJ case initiated by the FRY where a country publicly invoked the right of humanitarian intervention to justify an otherwise illegal intervention? I cannot recall any, I might be wrong but I think in all the other cases countries relied on the concept of humanitarian suffering as a policy argument.

2. You repeatedly refer to the ILC Draft. I might be wrong again, but I seem to remember that the ILC actually denied the applicability of the notion of necessity to use of force. Do you consider that interpretation being at odds with customary international law?


Mathias Vermeulen says

May 6, 2009


Just a quick reply to your first question. Indeed, no other state than Belgium has ever publicly invoked the right of humanitarian intervention to justify an otherwise illegal intervention.

As a Belgian I always wondered why they took this position, as Belgium traditionally is really keen on stressing the importance of the Security Council in matters like this.

A Belgian professor of International Law (Mark Cogen) quite bluntly stated in his 2003 'Handboek Internationaal Recht' that there is proof that customary law proved that there existed such a unilateral right to 'humanitarian intervention'. This professor was for some time legal advisor to the MFA, but i'm not sure if he was an advisor already in 1999. Maybe there's a link there...

Euan MacDonald says

May 6, 2009

A quick point, that may or may not be of interest: The "secret advice" given by the then Attorney General Lord Goldsmith to the UK Government on the legality of the war in Iraq, subsequently published in full, contains the following paragraph:

4. The use of force to avert overwhelming humanitarian catastrophe has been emerging as a further, and exceptional, basis for the use of force. It was relied on by the UK in the Kosovo crisis and is the underlying justification for the No-Fly Zones. The doctrine remains controversial, however. I know of no reason why it would be an appropriate basis for action in present circumstances.


I'm not sure what the status of this would be; possibly something less than a full public affirmation in the style of Belgium - but certainly not irrelevant in terms of establishing the opinio juris of the UK either, I wouldn't have thought.

Nehal Bhuta says

May 7, 2009

Simon Chesterman, in his thorough and scholarly book "Just War or Just Peace" does go someway to developing the argument that "humanitarian intervention" can be best understood as an "excuse" to what would otherwise be a delict. If other states accept the rationale proferred by the intervening state, they may still condemn it as a violation of the Charter but withhold further countermeasures or sanction as a means of recognizing that the violation may be excusable.

This is somewhat analogous to a necessity idea, although is not worked through (if I remember correctly) in terms of the notion of necessity in the DA on State Responsibility. But Simon does an admirable job of showing that there is some basis in state practice (the response of states to interventions in Uganda, East Pakistan, Cambodia) for this conceptualization.

Jan Kratochvil says

May 9, 2009

Dear Douglas,

very interesting thoughts. I have tried to explore this line of argument several years ago in an article, which can be found here ( I tried to argue that necessity is indeed available and that it was actually used (e.g. by UK in the Kosovo intervention).

There is one more problem with this argument yet. Even though the ILC articles do not deny the applicability of necessity to use of force Article 26 rules out circumstances precluding wrongfulness in cases of violation of jus cogens. So then it turns out to the question whether indeed the prohibition on the use of force is jus cogens and/or the jus cogens norm prohibits humanitarian intervention.


Douglas Guilfoyle says

May 12, 2009

Dear Jan and Tamás

I think the excellent comments have covered most points, other than where I stand on the issue of Article 26 of the ILC Articles. As Jan points out, Art 26 bars circumstances precluding wrongfulness being available in the case of breaches of jus cogens without referring to the use of force in terms. The ILC commentary does, however, refer to aggression as an example jus cogens.

On this point I favour the view of the early ILC Rapporteur on the subject, Roberto Ago who suggested we need to distinguish between the most grave uses of force (which would be aggression and prohibited as jus cogens) and lesser uses of force (which would still be unlawful but not contrary to jus cogens). See (1980) II YbILC at p.40.

I find this convincing as consent (a circumstance precluding wrongfulness) is generally accepted as excusing what would otherwise be violations of UN Charter Article 2(4) (stationing troops abroad, military overflight, etc). If one may consent to certain uses of force, necessity may likewise be available in principle.

This, of course, simply opens another debate about: (1) whether Ago was right; (2) where the boundary between these levels of force lies and how they might apply in the humanitarian intervention context; and (3) whether this is inconsistent with certain passages in Nicaragua suggesting the general prohibition on the use of force is jus cogens.

However, Jan and I are very much in agreement: the basic question remains whether the basic rule on the use of force itself prohibits humanitarian intervention.

Jan, thank you for the reference to your paper. My thanks also to the other comment-leavers for their very helpful contributions.


Erlend says

June 6, 2010

George P. Fletcer and Jens David Ohlin make a similar argument in Defending Humanity: When Force is Justified and Why (OUP 2007)