I found your exchange on the meaning of Art. 2(4) of UN Charter highly interesting. But, it seems to me that the interpretation of this provision cannot and should not be confined to the textual level. I humbly submit that the ultimate purpose of the prohibition of the use of force is to maintain international peace and security as much it is possible. That is why the exceptions (self-defence and authorization of UN Security Council) to this prohibition are strictly limited. The meaning of the phrase “in their international relations” is not to be found in any textual analysis of the terms used, but rather in a teleological approach. This prohibition thus applies to any use of force by a given State:
a) Outside its territory (to me the precise and ultimate meaning of “international relations”)
b) that breachs or threatens to breach international peace and security.
Whenever these 2 conditions are met, the nature or status of the other party against which force is used is not relevant for the purpose of application of the prohibition contained in Art. 2(4) of the UN Charter. A use of force that meet these thresholds can be lawful under the Charter only if based on one of the two exceptions.

I concede defeat on your grammatical point (compliments btw on your apparently excellent Chinese, and on your superb new article in the EJIL, which I’ve just read yesterday). But you seem to forget how the sentence begins: “All Members shall refrain in their international relations from the threat or use of force…” Their international relations means just that, relations between nations, i.e. states. Cf. Common Articles 2 & 3 of the 1949 Geneva Conventions. There is no inkling in the Charter or in Art. 1 of the Kellogg-Briand pact, which introduced the prohibition on the use of force, that states thought that they were binding themselves vis-a-vis non-state actors. (And if you disagree on the meaning of the word ‘international’, we can go and see what the travaux say ).

So sorry, but you cannot dismiss the fundamental distinction that international law has always (well, since the XIX century at least) made between states and non-states so easily, with a purely linguistic argument. Nor does Art. 31 VCLT assign such absolutely priority to language (the word ‘international’ aside for a moment) – we must also look at the context, the object and purpose, and state practice in the application of the Charter.

Again, for what it’s worth, your interpretation of Art. 2(4) may well be correct, but I at least will not be persuaded by your interpretation of the language alone.

Again I beg to differ. No perusal of the travaux is in order here. As you so eloquently put it above, “[i]t is the tools of interpretation referred to in Art. 32, such the travaux, which are subsidiary and can only be used if the meaning derived from the use of Art. 31 is unclear”- so we don’t even get there.

Let’s start with the English text of Article 2 para. 4:

“All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations.”

The meaning of the clauses is clear. We use basic rules of construction and arrive at two “commands”:

1. All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state.
2. All Members shall refrain in their international relations from the threat or use of force in any other manner inconsistent with the Purposes of the United Nations.

That’s what the comma and the “or” stand for. We don’t put all words in the sentence in a blender, as it were, and get to rearrange them as we see fit.

Moreover, the French text emphasizes this construction, employing three commas and negating the meaning you suggest completely by separating the use of force against a state from the other manners inconsistent with the Purposes of the United Nations (note the elegant “soit” … “soit”):

“Les Membres de l’Organisation s’abstiennent, dans leurs relations internationales, de recourir à la menace ou à l’emploi de la force, soit contre l’intégrité territoriale ou l’indépendance politique de tout Etat, soit de toute autre manière incompatible avec les buts des Nations Unies.”

I believe that pretty much closes the door on the alternative interpretation you suggested.

However, for completeness sake, I considered the remaining languages:

I am told that the Russian version can be equally separated into:

1. Все Члены Организации Объединенных Наций воздерживаются в их международных отношениях от угрозы силой или ее применения как против территориальной неприкосновенности или политической независимости любого государства.
2. Все Члены Организации Объединенных Наций воздерживаются в их международных отношениях от угрозы силой или ее применения [любым] образом, несовместимым с Целями Объединенных Наций.

Similarly, I was assured that a translation of the Arabic text yields the same connection between the clauses. Here is the original:

The Spanish text also follows the English:

“Los Miembros de la Organización, en sus relaciones internacionales, se abstendrán de recurrir a la amenaza o al uso de la fuerza contra la integridad territorial o la independencia política de cualquier Estado, o en cualquier otra forma incompatible con los Propósitos de las Naciones Unidas.”

When I read the Chinese version, it occurred to me that a literal translation could support your argument:

“各会员国在其国际关系上不得使用威胁或武力，或以与联合国宗旨不符之任何其他方法，侵害任何会员国或国家之领土完整或政治独立。”

For reasons rooted in Chinese grammar, the clause containing the reference to territory or political independence is put at the end, and a verb (”to violate”) is used, as otherwise the sentence would not make sense to a Chinese reader.

In sum, the French version strongly confirms the clear interpretation in English, and the other languages, with the exception of the Chinese grammar quirk, display the same construction. Hence, I find no reason for consultation of subsidiary means of interpretation.

I appreciate very much your statement above that we seem to be all in the same boat on policy. Yet, I also believe we have to take special care not to inadvertently deliver legal arguments to those who seek to put themselves outside the reach of the law.
That said, I realize it’s always easier to respond to a thesis than to advance it, so thanks again for putting your thoughts to the test!

I certainly find the argument that both of you make to be persuasive. That a textual argument can be made, however, is not the end of the matter. The second clause of Art. 2(4) can have a different purpose, that of qualifying the “territorial integrity or political independence” part, not the “any state” part of the previous clause. In other words, an alternative reading is that it simply says that the use of force against states is prohibited even if it does not infringe on their territorial integrity or political independence, so long as it is inconsistent with the purposes of the UN.

As far as I can recall the literature on the prohibition on the use of force enshrined in Article 2(4), I have never seen the suggestion that the prohibition extended to (some) non-state actors. It likewise seems pretty inconceivable to me that states sitting in San Francisco more than sixty years ago would have agreed to such a prohibition. In any case we would need to peruse the travaux etc. in order to reach a conclusion on your textual argument — something that I might do later when I go back to Cambridge and have a proper library at my disposal.

At any rate, we agree completely on the policy. I, too, dislike the fact that Gaza’s non-state actor status might create a vacuum. But again, filling this vacuum with norms requires a showing that the law has overcome the inter-state paradigm, and has done so precisely in the field where states still matter the most, the use of force.

I have followed your discussion with great interest – it is always enjoying to read the exchange of bright and sharp legal arguments – even on such a sad topic as the tragedy unfolding in Israel and Gaza.

However, what strikes me is that so far no one of you has come up with the idea to utilize Article 2 (4) of the Charter fully. As we know, it says that all Members shall refrain from the use of force against States “…or in any other manner inconsistent with the Purposes of the United Nations.” If this is seen as an emphasis of the general prohibition and not as an exception, it points to other cases of the use of force that are prohibited beyond the use of force against States. So you do not necessarily need a State to trigger Article 2 (4), but rather force inconsistent with the purposes of the UN.

Article 1 (2) of the Charter then ranks the self-determination of peoples among the purposes of the UN. Ergo, I think it is sound to argue that any established and recognised self-determination unit enjoys the protection of Article 2 (4). Palestine, of course, is recognised as such a self-determination unit (see Security Council Resolution 1850 (2008) as latest example) and should thus enjox the protection of Article 2 (4).

However, as Andreas has correctly pointed out, Gaza is a renegade province of the sel-determination unit – and thus the situation seems to get a bit more complicated. However, I do not think that this alters the picture decisicely: A coup or other internal strife does not derive a State from the protection of Article 2 (4) – and neither should it derive a recognised self-determination unit from the same protection.

Israel thus needs a justification for its actions – which may only be found in Article 51 (or in the customary law of self-defense). Consequently, Israel has to accept the limits of self-defense, i.e. the general margin of proportionality.

It is with great interest that I have followed your comments regarding the operation of Articles 2 para. 4 and 51. As always, I admire your clarity of thought. However, I have the distinct feeling that your construction of Article 2 para. 4 misses the mark, in effect creating a dangerous legal vacuum, although the Charter’s broad drafting does offer little support for this interpretation.

You asked above for authority to the effect that there is in international law a prohibition on states to use force against non-state actors outside their territory, even if that use of force does not infringe on the sovereignty of another state. I believe that Article 2 para. 4 itself may provide us with an answer.

Your clear-cut rejection of such a prohibition seems rooted in your consideration that “no state claims sovereignty or title over Gaza, and the sovereignty of no state was infringed by Israel’s use of force.” Hence, you conclude that Article 2 para. 4 does not apply. This rigid interpretation of Article 2 para. 4 does not seem appropriate to me, not on the plain meaning of Article 2 para. 4 and certainly not in the context and with a view to the object and purpose of Article 2 para. 4 and the Charter.

So let’s step back and take a look at the text. Article 2 para. 4 consists of two half-sentences, the first of which you emphasize, and the second of which I deem to be important to assess the validity of your reasoning. The full article reads as follows:

“All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations.”

It seems to me that you are simply dropping the second part under the table, when claiming that Article 2 para. 4 could not possibly apply to the Gaza situation. You may have very good reasons why you deem this part irrelevant, but unfortunately you fail to articulate them.

However, the second part may be very important in the case at hand. Instead of sticking to the narrow language of “territorial integrity or political independence of any state” the article also prohibits the use of force “in any other manner inconsistent with the Purposes of the United Nations”. Whenever Article 2 para. 4 is echoed in the Declaration on Friendly Relations, the full provision is used.

I would argue that the savings clause in the second part of Article 2 para. 4 was drafted to avoid a simple a contrario interpretation such as yours. In the case of Gaza, giving meaning to the second clause serves to avoid the legal vacuum with respect to the ius ad bellum into which Israel’s actions would fall according to your interpretation

More specifically, the second clause of Article 2 para. 4 refers us to the purposes of the United Nations. Article 1 para. 1 provides that states are held

“1. To maintain international peace and security, and to that end: to take effective collective measures for the prevention and removal of threats to the peace, and for the suppression of acts of aggression or other breaches of the peace, and to bring about by peaceful means, and in conformity with the principles of justice and international law, adjustment or settlement of international disputes or situations which might lead to a breach of the peace; …”

In my view, given (as you also assume) that Gaza is not considered part of Israel, Israel is bound to refrain from use of force in Gaza that is inconsistent with the purposes of the United Nations. By taking unilateral measures of force, Israel presumptively violated Article 2 para. 4 read together with Article 1 para. 1 mandating specifically _collective_ measures against threats to the peace.

Of course, Israel may claim self-defense as enshrined in Article 51, but, as you also agree, reliance on Article 51 will be tied to a proportionality analysis.

While I strongly disagree with you on the law, I want to thank you for having kicked off this important discussion.

P.S.: If your interpretation of Article 2 para. 4 were correct, namely that no situation not involving the threat or use of force against the territorial integrity or political independence of any state could trigger Article 2 para. 4, the second clause of the article would be completely devoid of effect. According to the maxim “ut res magis valeat quam pereat” an interpretation giving meaning to the clause is to be preferred.

As for proportionality, you again provide no authority for your position that it is a broad principle independent of self-defense.

Be that as it may, it was as always a great pleasure to debate the law with you, even if we have to disagree.