The UN Soleimani Report and the U.S. Article 51 Notification

by | Sep 24, 2020


On July 9, 2020, the UN Special Rapporteur on Extrajudicial, Summary or Arbitrary Executions released a report on the legality of targeted killing by drone strikes. The backdrop for the report is the U.S. strike against Qasem Soleimani on January 2, 2020. And, in fact, although the report frames its contents in more general terms, it includes an extended case study on the legality of the Soleimani strike.

The report contains an interesting—and problematic—connection between the UN Charter’s notification requirements for the use of force in self-defense under Article 51 and the lawfulness of the resort to self-defense itself. This article discusses the requirements for notification to the UN Security Council for acting in self-defense under Article 51 generally and considers whether the United States met those conditions in the specific case of Soleimani. In doing so, it emphasizes the two different legal obligations contained in Article 51—a State’s duty to notify the Security Council when it has used force in self-defense and the legality of that use of self-defense.

The Facts

On January 2, 2020, a U.S. airstrike killed Qasem Soleimani, the commander at the time of the Quds Force within the Islamic Revolutionary Guard Corps in charge of Iran’s military operations across the Middle East. On January 8, 2020, the U.S. Ambassador to the UN submitted an official letter to the President of the Security Council in which she declared that the United States took actions “in the exercise of its inherent right of self-defense” including “an operation on January 2, 2020, against leadership elements of Iran’s Islamic Revolutionary Guard Corps Quds Force on the territory of Iraq.”

On the same day that the UN Special Rapporteur issued her report—July 9, 2020—U.S. Secretary of State Michael Pompeo responded that “[w]e reject the report and opinions” and that the “conclusions are spurious.” Secretary Pompeo asserted “[t]he United States is transparent regarding the international law basis for the strike. As we outlined in a January 8, 2020 letter to the UN Security Council submitted in accordance with Article 51 of the UN Charter, the strike was undertaken in the exercise of the United States’ inherent right of self-defense.”

Article 51 Reporting Requirement

Article 51 of the UN Charter, after securing States’ inherent right of self-defense, asserts that “[m]easures taken by members in the exercise of this right of self-defence shall be immediately reported to the Security Council” [emphasis added]. This reporting requirement is a reflection of the Security Council’s “primary responsibility for the maintenance of international peace and security.” However, neither the Charter nor the Security Council offer any further guidance on the scope or nature of the reporting requirement.

Notwithstanding the lack of textual guidance, the Special Rapporteur’s report recommends that States, “[w]hen invoking Article 51, provide a thorough justification, including evidence of an ongoing or imminent attack and the proportionality of the measures to be taken in response” (para 92(a)). The UN report laments the “poor quality of the Article 51 reports” and the fact that States “provide little by way of evidence” of support in their Article 51 reports to the Security Council (para 68). It continues by stating that because of “the importance of Article 51 to global peace and security, the UN principal mission, it seems reasonable to suggest that States who invoke Article 51 to justify targeted killings by drones or other tools ‘owe the international community a thorough justification, not a cursory report.’” (para 67).

Specifically, in regard to the U.S. Soleimani strike, the UN report includes a number of criticisms contending the U.S. letter of notification lacked evidence and justification. For instance, the report states “nowhere in the letter does the United States state that Iran had ‘overall control’ over these groups” (Annex A, para 60), referring to the U.S. notification’s reference to “Qods Force-backed militia groups in Iraq.” In another example, the report states that “[a]t no point in its Art. 51 letter, filed a full 5 days after the strike, does the United States state that it was defending against an imminent attack” (Annex A, para 61).

Not only does the Special Rapporteur’s report maintain that the Article 51 notification requirement should include evidence and justification for an attack in self-defense, but—importantly—it also puts forth that the U.S. notification “should be the sole basis in determining the legality of the strike under the Charter” (Annex A, para 55) [emphasis added]. Further complicating matters, notwithstanding this assertion, the report blurs evidence and justifications for the strike put forth by the United States in the notification letter and subsequent U.S. statements.

No Requirement for Evidence

Despite the UN report’s contention, there is no legal obligation that requires the Article 51 submission to provide substantial proof to support actions in self-defense. The lack of any express requirement in the UN Charter beyond the reference to report “measures taken” makes this clear.

As Yoram Dinstein observed, while the Article 51 report must “consist[], at a minimum, of a plain notification,” “[t]here is nothing in Article 51 to substantiate a claim, occasionally made, that the report must provide clear evidence.” This view is supported by the Charter’s drafting history. Proposals in the draft text include requiring that reports would contain an obligation to keep the Security Council “fully informed” of self-defense activities “at all times” (Volume XII, Document 576). Significantly, the final Charter agreement signed at the 1945 San Francisco Conference abandoned the broader proposal “to be fully informed… at all times” in favor of the less stringent obligation contained in Article 51. The practice of States supports the absence of any requirement of factual justification. As noted by one author, reports “submitted by States [are] generally extremely cursory, for the most part including little factual or legal detail.”

Furthermore, the equally authentic French version of Article 51 uses the phrase “portées a la connaissance du Conseil de Sécurité” rather than “reported to the Security Council.” The French text directly translates as “brought to the notice” or “brought to the attention” of the Security Council. The law embodies a more flexible approach rather than submission of the formalized conception of “a report” implied by the English text.

What this makes clear is that the UN report essentially suggests adding requirements to Article 51 that do not exist as a matter of law. Moreover, it is mixing up two different legal issues: the requirement to notify the Security Council on the use of force in self-defense and the legality of the resort to self-defense itself.

Immediately Report

The Article 51 requirement to “immediately report” raises the question of the timeliness of the U.S. submission five days after the Soleimani strike. Indeed, while the Special Rapporteur’s report does not dwell on the issue, it suggests that the U.S. letter may have been untimely.

Requiring a timely report provides the Security Council the opportunity to implement the Charter’s mandate “to take effective collective measures for the prevention and removal of threats to the peace.” This relates to Article 51’s condition that States taking actions in self-defense may do so “until the Security Council has taken measures necessary” to restore international peace and security. Of course, the complementary relationship between a State’s inherent right of self-defense and Security Council Chapter VII enforcements mechanisms does not answer the question whether the five days between the Soleimani strike and the U.S. notification to the Security Council, is sufficiently timely.

A comprehensive study of Article 51 reports from the Charter’s founding in 1945 until the beginning of 2019 revealed that the majority of reports were submitted within one week after actions were taken in self-defense. The U.S. notification to the Security Council was within the range of consistent State practice.

Legal Implications of Failure to Report

The most notable judicial reference to the reporting requirement is the International Court of Justice’s Military and Paramilitary Activities in an against Nicaragua judgment. Although it deals with inquiry under customary international, as one of the few cases that deal with this issue, it is worth mentioning. In that case, the Court asserted a failure to report a use of force in self-defense would be legally relevant as only “one of the factors indicating whether the State in question was itself convinced that it was acting in self-defence.” In other words, a State’s failure to comply with the reporting obligation does not divest it of the right of self-defense.

While the Court’s assertion was limited to self-defense under customary international law, in the context of Article 51 the Court states only that the reporting requirement “should be respected” [emphasis added]. Thus, arguably, even if the United States’ Article 51 submission were insufficient, standing alone this would not render an otherwise lawful use of force unlawful. As a separate matter, reporting is a treaty obligation imposed on States. Therefore, failure to comply is an internationally wrongful act through omission. A failure to report may expose a State to legal remedies, such as assurances and guarantees of non-repetition or reparation.

Concluding Thoughts

The Article 51 reporting obligation requires States to promptly notify the Security Council of its actions taken in self-defense. It does not require States to provide clear evidence “to the Security Council for public examination,” as the Special Rapporteur’s report suggests it should. Perhaps a more important question is whether the United States—and other States as well—should have to provide such evidence.

Responsible States of the international community seek to support the rule of international law. In many situations, it may make sense to provide the evidentiary basis for a use of force. Doing so can build credibility within the international community. States may also release such information in order to “name and blame” the State against which they are acting in self-defense. More details also allow the international community to identify, interpret, and apply evolving international law norms based on the conduct of States.

In contrast, States may be reluctant to disclose highly sensitive classified information or intelligence that might undermine their national security or diminish operational effectiveness. Sometimes States receive information or intelligence from allies and partners who prefer to remain anonymous.

Regardless, States may weigh the costs and benefits of disclosing more than international law requires as a policy matter. They are not, however, obligated as a matter of law to provide evidentiary proof the action was in self-defense in their Article 51 report. Accordingly, in the case of the Soleimani strike, the United States complied with its Article 51 reporting obligation.


Lieutenant Colonel Durward Johnson (USA) is a military professor of international law and the Associate Director for the Law of Land Warfare in the Stockton Center for International Law at the U.S. Naval War College. The views expressed here are his own and do not represent those of the U.S. Naval War College, the Department of the Navy, the Department of Defense, or any part of the U.S. government.