US troops and bases are located in Syria without UN sanction or the Syrian government's permission.

UN Article 2.4 states:

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.

UN Article 51 states:

Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security.

To clarify -

I understand that the US base their actions on article 51, but do they also violate 2.4 or not? Is Art. 51 a legal exemption to avoid Art. 2.4? Are both contradictory and a thus a "loophole" in International Law? How are both to be interpreted together?

Does the United States violate the UN Charter or International Law in Syria? Or is it using a loophole to skirt International laws?


3 Answers 3


i understand that US base their actions on article 51, but they also violate 2.4 or not? Does they use a contradiction in International Law and what the way of it's solving?

Well, the principles of the UN charter are sometimes contradictory or at least in tension, so depending on which one you favor in a particular context results/positions can be different. E.g. Russia is arguing that 2(4), which is about territorial integrity, is not relevant to Ukraine or Georgia. (Russia claimed that 51 is more relevant there.) And al-Assad agrees with that (ibid). I'm not sure there's much more to be said here.

Legally speaking 51 is an exemption from 2(4):

The UN Charter recognises two exceptions to Article 2(4): military enforcement action authorised by the UN Security Council, in response to a determination of the existence of a threat to the peace, breach of the peace or act of aggression and the right of individual or collective self-defence in response to an armed attack. While further exceptions to Article 2(4) have been advocated, the most prevalent of which has been the doctrine of humanitarian intervention, these have been controversial and there is at best limited consensus upon their existence.


The right of self-defence is governed by Article 51 of the UN Charter, which provides that:

Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security. [...]

Which is why you see those arguments in particular cases, esp. since when one of the P5 veto something, the UNSC can't agree to anything in that case.

Generally speaking, such disputes arise because facts on the ground or at least the interpretation thereof is contested. E.g. [I may be over-simplifying these conflicts a bit, but I don't think it's worth going into the details given the other questions that do that):

  • Russia and Syria say that there was never a reason for the US to intervene against ISIS (in Syria at least). The US disagrees and even claims (still, I think, although I've not checked this since my last answer on the topic) that ISIS is still a threat. (Back in Obama's time the list of official reasons was longer, IIRC, including protecting the Kurds, which have their own quasi-state in Syria. But that went out with Trump's presidency. TBH, I've not been able to find what Biden has said, if anything, on this issue.)

  • Turkey claims the right to occupy a "buffer zone" in northern Syria to protect itself against Kurdish and other attacks. Syria has called for the withdrawal of the Turkish troops, although in this case (AFAIK) Russia hasn't been as adamant in joining that call. Instead it hosted various talks between Syria and Turkey, in an attempt to semi-legalize the situation.

  • As another example, Russia claims Ukraine attacked its Russian-passport-holding citizens of Ukraine [or dual nationals]. And Russia even claimed this was part of a genocide. Ukraine says it was defending its territory against separatists.

And since in all these conflicts the P5 is divided (sometimes bitterly), the UNSC can't do anything, thus the interpretation of "who is right" in terms of applying international law (and the UN charter in particular) to specific facts is left to the "peanut gallery" (UNGA etc., which have no legal force, although perhaps they have some moral weight) and so countries act outside of UNSC explicit mandates to help or hinder whomever they think was the "bad guy" (or sometimes plain ignore the conflicts).

Much has been made in a couple of answers here about the 2004 ICJ decision which states some non-controversial stuff like 51 being invokable when one State attacks another. But that decision [summary] also says:

Self-defence: Article 51 of the Charter

Attacks against Israel not imputable to a foreign State

Threat invoked to justify the construction of the wall originating within a territory over which Israel exercises control Article 51 not relevant in the present case.

So you cannot invoke article 51 when the attack originates from territories you control. The ICJ ruled that Israel was controlling the OPT so it couldn't claim that terrorist attacking from there were based in a foreign state. Reading in that that 51 never applies to cross-border attacks conducted by non-State actors is reading too much into that decision, IMHO.

Also, in his dissent in that decision, one judge pointed out that ICJ had ruled different in the Nicaragua case:

I do not agree with all that the Court has to say on the question of the law of self-defence. In paragraph 139 the Court quotes Article 51 of the Charter and then continues “Article 51 of the Charter thus recognizes the existence of an inherent right of self-defence in the case of armed attack by one State against another State.” There is, with respect, nothing in the text of Article 51 that thus stipulates that self-defence is available only when an armed attack is made by a State. That qualification is rather a result of the Court so determining in Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America) (Merits, Judgment, I.C.J. Reports 1986, p. 14). It there held that military action by irregulars could constitute an armed attack if these were sent by or on behalf of the State and if the activity “because of its scale and effects, would have been classified as an armed attack . . . had it been carried out by regular armed forces” (ibid., p. 103, para. 195).

So, at least in that case the judgments was nuanced as a matter of "scale and effects" as well as whether the forces could be considered the proxy of another state. This could still leave something like ISIS outside the scope of 51 (by ICJ precedents), but the ICJ had not had to grapple with that phenomenon before, where a terrorist organization captures vast swaths of territory and claims to be a new state.

(And even regarding Israel/OPT, one should be reminded that in 2004 Israel had not yet even withdrawn their ground forces from Gaza [that happened a year later], so the level of [ground] control was different than today. Albeit the dispute there was nominally only about some wall in the West Bank.)

AFAIK, Syria is yet to bring a case at the ICJ for US violations of 2(4) on grounds that 51 doesn't apply there. (Syria probably cannot bring one directly because the US would object--adjudication at ICJ requires both sides to consent. But Syria/Russia seem to have yet to muster even the UNGA votes for an advisory ICJ opinion in that respect, as happened in the Israel/OPT wall case.)

  • Comments have been moved to chat; please do not continue the discussion here. Before posting a comment below this one, please review the purposes of comments. Comments that do not request clarification or suggest improvements usually belong as an answer, on Politics Meta, or in Politics Chat. Comments continuing discussion may be removed.
    – JJJ
    Commented Oct 26, 2023 at 20:59
  • "Legally speaking 51 is an exemption from 2(4)" - is it an official position? what documents or application of authorized persons can proof it? Is the Reiss Center on Law and Security same as official voice of the US government? Commented Oct 27, 2023 at 7:54
  • 1
    @άνθρωπος As it clearly says "nothing in the present charta", it has to be considered lex specialis which overrides other, more general provisions. Thus, it obviously allows for violations of 2(4) given an attack has occurred and if not doing so would impair the ability of self-defense, based on basic juridical principles which apply everywhere. The problem remains that the UNSC should determine the limits and proportionality of this override, which it doesn't as long as the P5 disagree. Commented Oct 27, 2023 at 11:26
  • @PhilipKlöcking i have some doubts: since when has wikipedia been proof of the UN Charter interpretation? Commented Oct 28, 2023 at 10:22

On the general relation between 2(4) and 51

The UN lists all law practice reports on Article 2(4) of the Charter. In the latest report, it says:

During the period under review, the High-level Panel on Threats, Challenges and Change, established by the Secretary-General, prepared a report entitled “A more secure world: our shared responsibility”. The report stated that there were only two exceptions to the prohibition under Article 2(4), i.e. self-defence under Article 51 and military measures authorized by the Security Council under chapter VII. In particular, the report discussed the question of whether a Member State was entitled to exercise self-defence against a threat that was not imminent and argued that, if there was enough evidence to take pre-emptive action without an imminent threat, the Member State should request the authorization of the Security Council before taking any action.

This means that Article 51 supersedes Article 2(4) and allows for immediate action (without UNSC sanction) in cases of an imminent threat.

Precisions made by the International Court of Justice

The same document lists two interesting judgements which clarify its stance on the relation between 2(4) and 51:

The Court noted that Article 51 of the Charter recognized the existence of an inherent right of self-defence in the case of an armed attack by one State against another State.

And, in another case:

[... T]he [state] had to show that attacks had been made upon it for which [the other state] was responsible; and that those attacks were of such a nature as to be qualified as “armed attacks” within the meaning of that expression in Article 51 of the Charter, and as understood in customary law on the use of force.

Thus, the ICJ does indeed prefer a strict interpretation and explicitly excludes the use of Article 51 as a justification for military intervention on foreign territory against terrorists (or pre-emptively, as far as I can tell). In any case though, the court explicitly acknowledged that in the case of an armed attack of one state against another, Article 51 can serve as a justification of violations of Article 2(4).

Either way, according to the ICJ, the US presence in Syria (as Türkye's) on the grounds of Article 51 would be unlawful since Syria never launched an armed attack against either of these states.

On the reality of the practice of international law

Notwithstanding the position of the ICJ, it is only the UNSC that could provide any meaningful decision, especially regarding the US since they never acknowledged the ICJ's judgements as compulsory (it goes without saying that Russia and China did not as well). In most cases, the ICJ may be asked for its opinion but the UNSC may well decide contrary to the ICJ's stance and has done so several times (see the documents for explicit examples).

Thus, for all practical considerations, if the US (or others, as did Russia in Georgia and Ukraine) justify their actions on foreign grounds with Article 51, no matter the exact wording, and there is someone putting a veto on any resolution condemning this act, that is the de facto situation. And even if there are resolutions, if consequences are vetoed (like with Israel's de facto and de jure violations of existing resolutions for decades), nobody actually cares for what the theory says. That is sadly, the nature and reality of our current international law.

Why the "unable or unwilling" doctrine is pretty convincing

Article 51, both in its wording and systematically, puts the right of self-defence as a very high good, in fact even more important than territorial integrity per se. Now, if one was to accept the ICJ's strict interpretation, a state would, in theory, have no right to defend itself if, for example, a non-state group would establish bases (up to ICBM starting ramps) in a failed state or one the does not intervene in such actions on its territory. Thus, the state would have no legal means whatsoever (other than asking the UNSC pretty please) to defend itself against this kind of threat, imminent attack, or even actual attack from foreign territory.

This, in turn - and that is why the doctrine is popular not only with the US - cannot be the intended outcome. Basically, the wording and a strict interpretation of Article 51 are based on the premise that either no non-state organisation could ever be a substantial threat to a state or such threat would never be tolerated among member states. This premise does obviously not hold. Thus, it makes a lot of sense to say that - obviously as a last resort - if there are no other means for self-defense, a temporary intervention, lasting only for as long and insofar it is absolutely necessary to make attacks on one's state impossible, should be allowed.

Of course, this opens another can of worms (proportionality in particular) but there's that..

  • Great work! You proved that The report have claim that "The report stated that there were only two exceptions to the prohibition under Article 2(4), i.e. self-defence under Article 51". But it is still not prove that the UN Charter or ICJ support this rhetoric. Ofc it can be usable to create a new judgment act, but does such acts exist? Commented Oct 28, 2023 at 15:23
  • "nobody actually cares for what the theory says" - Russia does, and did. Don't know about Israel, but Russia definitely cares. But thank you. Commented Oct 28, 2023 at 15:24
  • And about the 3 part. It is definitely very interesting and it should work if one no. Because 1 billion sanctions on Russia))). SO what is the US logic in this narration? Commented Oct 28, 2023 at 15:29
  • @άνθρωπος What? Regarding the first comment: The court explicitly discusses 51 as an exception to 2(4)! What's not to understand about that? Read the freaking document! Regarding the second one: Russia used the very same arguments for its interventions in Georgia and Ukraine. Russia tramples on international law just as much as the US and other states. Commented Oct 28, 2023 at 15:30
  • But only Russia have sanctions bonus or not? Not the US? Why? What the different if "unable or unwilling"? OR sanctions with the principle "unable or unwilling" too? Commented Oct 28, 2023 at 15:31

The clarify of the question was the wrong statement about the presence of the US forces in Syria because i have no confirmation from official sources on what grounds the US presence correlates with the UN Charter's Article 51 and which article of this UN Charter justifies it today.

So, the claim that intervention can be based on article 51 looks doubtful. But if it is true official version it would like to see a competent confirmation of this version.

But i found "the judge-head" of the UN - it is the the International Court (ICJ)

And the ICJ have the advisory opinions to the cases and the UN Charter articles.

So for this moment im considering as a similar precedentt the following:

On 13 July 2004 ICJ Advisory opinion on the Legal Consequences of the Construction of a Wall in the OPT


Article 51 of the Charter . . . recognizes the existence of an inherent right of self-defence in the case of armed attack by one State against another State. However, Israel does not claim that the attacks against it are imputable to a foreign State.

The Court also notes that Israel exercises control in the Occupied Palestinian Territory and that, as Israel itself states, the threat which it regards as justifying the construction of the wall originates within, and not outside, that territory. The situation is thus different from that contemplated by Security Council resolutions 1368 (2001) and 1373 (2001), and therefore Israel could not in any event invoke those resolutions in support of its claim to be exercising a right of self-defence.

Consequently, the Court concludes that Article 51 of the Charter has no relevance in this case.” (Para. 139.)

And here-6:

Article 51 of the Charter provides that “Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if(!) an armed attack occurs against a Member of the United Nations . . .” Moreover, in the resolutions cited by the Court, the Security Council has made clear that “international terrorism constitutes a threat to international peace and security”

And here-6 too precedent:

In its resolution 1368 (2001), adopted only one day after the September 11, 2001 attacks on the United States, the Security Council invokes the right of self-defence in calling on the international community to combat terrorism. In neither of these resolutions did the Security Council limit their application to terrorist attacks by State actors only, nor was an assumption to that effect implicit in these resolutions. In fact, the contrary appears to have been the case. (See Thomas Franck, “Terrorism and the Right of Self-Defense”, American Journal of International Law, Vol. 95, 2001, pp. 839-840.)

"In the aftermath of the attacks, many U.S. citizens believed that the attacks had "changed the world forever." The Bush administration announced a war against terrorism, with the goal of bringing Osama bin Laden and al-Qaeda to justice and preventing the emergence of other terrorist networks." Wiki

11/11 only because => al-Qaeda is a legitimate target by the UN Charter 51!!

And here-9(probably if US citizens are located there):

Paragraph 6 of Article 49 of the Fourth Geneva Convention also does not admit for exceptions on grounds of military or security exigencies. It provides that “the Occupying Power shall not deport or transfer parts of its own civilian population into the territory it occupies”.

So, my clarify is not actual for now -

I understand that the US base their actions on article 51, but do they also violate 2.4 or not? Is Art. 51 a legal exemption to avoid Art. 2.4? Are both contradictory and a thus a "loophole" in International Law? How are both to be interpreted together?

Because, i am not understanding why the US did it by the UN Charter logic and i can't find an official version of the US why they do it now.

But the other questions are still actual, i don't have answers on them.

But i understand that:

ICJ said that 51 is apply to 2.4 but in "if an armed attack occurs against a Member of the United Nations" reason

But i don't know, have the US claimed that ISIL had attack occurs them?

Argumentation about "unable or unwilling" doctrine or "Legally speaking 51 is an exemption from 2.4" does not looks sufficient for use the Article 51, because it creats contradictory between 51 and 2.4. And the source Just Security, that claimed "Legally speaking 51 is an exemption from 2.4" - doesn't look as does not look authorized because it is non-government or the UN institution. It is good as consultation opinion, but it have no a competence status to be a judgement base in the question.

But the problem, i have no information with an official reason of the US version - at start, and at today too.

The answer:

  1. At the UN Charter logic set out in ICJ interpretation there is no contradictory between 51 and 2.4.

  2. Also i have no information about the US official claims about ISIL attack which could be the basis for the Artical 51 usage. But They said "because 51" as i know. As i understand that was not "if an armed attack occurs" by ISIL.

  3. The contradictory appears by the "unable or unwilling" doctrine(officially) and/or "Legally speaking 51 is an exemption from 2.4"(don't know officially status) owned apparently to the US side. This claims are cheating and erasing the sense of "if an armed attack occurs" (2). Therefore it needs "Legally speaking 51 is an exemption from 2.4". But i don't know is it official justification or not. But also it can't be considered the UN official interpretation.

  4. i have no information does the 3 usable to justify intervention in the US in Syria and is this a today excuse to stay there now.

  • 1
    That's clearly false. 51 states "Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs", which clearly includes 2(4) as part of the Charter. It is a totally normal practice that rules within a single body of legislature can override/contradict one another. As I already pointed out, this is simply a special case of lex specialis. It is also common sense that this only works if it is necessary to violate 2(4) to fulfil 51, which is exactly where the "unwilling or unable" doctrine comes into play. Commented Oct 28, 2023 at 7:24
  • @PhilipKlöcking "It is a totally normal practice" - probably, but in the US court system, not the UN. If you have proofs at the UN law usage it will be interesting for me. But i think it is not work this was for the Article 51, im sure, for today. 'It is also common sense that this only works' - there is no 'common senses', only the Law, UN's one, so no, sorry. "unwilling or unable" doctrine - is not the UN doctrine, or Geneva's, or else International. Philip, i know, you are a wise man, don't be common in senses, be justy, thank you. Commented Oct 28, 2023 at 7:48
  • @PhilipKlöcking you say that is lex specialis, but i can say it is extension of sense. So, i have some doubts. But if you can proved your words according to the UN or ICJ documents, i can to agree with you without any of doubts. Commented Oct 28, 2023 at 10:17
  • No body of laws I know of doesn't include terms that narrow or except other terms. Upthread, there's examples of ICJ clarifying that 51 except 2.4 (before delving into whether 51 applies to the case at hand). There's no reasonable alternate reading to Article 51.
    – bharring
    Commented Oct 30, 2023 at 17:43

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