The United States’ military operation against Iran has raised important questions about the legality of the strike and potential fora in which Iran could bring claims against the United States. Although, as recently argued on this blog, the International Court of Justice (“ICJ”) may not have jurisdiction to hear Iran’s claims based on the United States’ latest attack, there is still a possibility that the ICJ could resolve Iran’s earlier claims based on the 2020 assassination of Iranian general Qasem Soleimani under the first Trump Administration. A previously untested legal basis in the relationship between the parties—the Convention on the Prevention and Punishment of Crimes against Internationally Protected Persons (“Protected Persons Convention” or “Convention”)—may offer a novel jurisdictional avenue for Iran before the ICJ.
ICJ as a forum for US-Iran Disputes
For decades, both the United States and Iran looked to the International Court of Justice (“ICJ”) as a potential forum for resolving disputes between them. In 1979, the United States sought the assistance of the ICJ in relation to American hostages kidnapped in the U.S. embassy in Tehran. Iran subsequently brought four cases against the United States in the ICJ, the three most recent of which were brought under the compromissory clause of the 1955 US-Iran Treaty of Amity. In essence, the ICJ served as an important safety valve for peacefully resolving tensions, including when the first Trump administration withdrew from the Joint Comprehensive Plan of Action (i.e., the so-called “nuclear deal”) concluded by Iran and the Obama administration, prompting Iran to institute proceedings under the Treaty of Amity once again.
In 2018—in response to Iran’s suit—the first Trump administration announced the United States’ withdrawal from the Treaty of Amity, leaving the parties with few options for unilateral recourse to courts or tribunals to resolve disputes through peaceful means. Tension mounted in 2020 when the United States assassinated Iranian general Qasem Soleimani in a drone strike in Baghdad.
In the wake of the United States’ most recent attacks on Iran, the apparent weakness of Iran’s military, and the entry into force of a ceasefire, Iran may now be particularly interested in legal avenues to score victories that might help it save face. Although the ICJ may not have jurisdiction over claims based on the latest conflict, it remains a potential forum for Iran to challenge the legality of the Soleimani assassination under the Protected Persons Convention. Indeed, Iran may have kept this claim in its back pocket in the event that nuclear negotiations with the United States failed.
Soleimani’s Assassination
According to Iraq’s then-Prime Minister, Soleimani had travelled to Iraq in connection with Iraq-mediated negotiations between Saudi Arabia and Iran. (“I was supposed to meet him in the morning the day [Soleimani] was killed, he came to deliver a message from Iran in response to the message we had delivered from the Saudis to Iran.”) Then-U.S. Secretary of State Pompeo denied Iraq’s account without elaboration. In response to the attack, Iran pledged “martyr’s revenge.” But it also quietly pursued a peaceful alternative. In January 2024, Iran announced that, beginning in September 2023, it twice invited the United States to negotiate a dispute under the Protected Persons Convention, and that it plans to submit an application to the ICJ.
The Protected Persons Convention
The United States and Iran have both ratified the Convention without reservations. Article 13(1) of the Convention provides that:
Any dispute between two or more States Parties concerning the interpretation or application of this Convention which is not settled by negotiation shall, at the request of one of them, be submitted to arbitration. If within six months from the date of the request for arbitration the parties are unable to agree on the organization of the arbitration, any one of those parties may refer the dispute to the International Court of Justice by request in conformity with the Statute of the Court.
Twenty-one months have now passed since Iran reportedly first requested negotiations. If the negotiations “failed” or became “futile or deadlocked” (Armenia v. Azerbaijan, Preliminary Objections Judgment ¶¶ 52-53), Iran would have been entitled to request the submission of the dispute to arbitration. And if Iran did request arbitration more than six months ago and the parties did not agree on its organization, Iran may now be able to refer the dispute to the ICJ.
Moreover, assuming Soleimani was in fact in Iraq on a special diplomatic mission, which seems plausible if Iraq’s account is accurate, his killing may have indeed violated the Protected Persons Convention, subject inter alia to questions about the United States’ duties to an invitee of Iraq and the relationship between the Convention and IHL.
Article 3(1) of the Convention provides that “[e]ach State Party shall take such measures as may be necessary to establish its jurisdiction over the crimes set forth in article 2 … [w]hen the alleged offender is a national of that State.” Crimes are defined in Article 2 to include, inter alia, “murder” and “other attack[s] upon the person or liberty of an internationally protected person.” The duty to exercise jurisdiction extends not only to the party on whose territory the crime occurred, but also to “[e]ach … Party” based on the nationality of the alleged perpetrator. Article 3(1)(b). This suggests that if Soleimani were an internationally protected person, the United States could have an obligation to establish jurisdiction over an attack on Soleimani by its nationals.
Article 1(1)(a) includes in the definition of an “[i]nternationally protected person” a “Head of State,” “Head of Government” or “Minister of Foreign Affairs.” Soleimani, a general, was none of these. However, Article 1(1)(b) expands the definition to include “[a]ny representative or official of a State … who, at the time when and in the place where a crime against him . . . is committed, is entitled pursuant to international law to special protection from any attack.”
The Convention does not define who is “entitled pursuant to international law to special protection.” However, the ILC commentary states that the phrase “general international law” (changed to “international law” in the final version) was “designed to take into account developments in international law such as the need for protection of representatives of the sending State in a special mission and members of the diplomatic staff of the special mission within the meaning of the Convention on Special Missions” (emphasis added). The Convention’s definition of an internationally protected person was thus framed to encompass the applicable international law on special missions.
Inviolability of Special Missions
The United States has neither signed nor ratified the Convention on Special Missions. Nevertheless, it is bound by any applicable customary international law on special missions, including to the extent the Special Missions Convention reflects customary rules.
According to the leading treatise on special mission immunity under customary international law, the “minimum requirements for an official visit attracting immunity”—or, as in this case, “inviolability”—as a special mission are 1. “the need for the visitor to represent the sending state” and 2. “the need for the receiving state to consent to the visit as one attracting immunity” (Michael Wood, The Immunity of Official Visitors (2012) at 66, 69 (capitalization omitted); see also Hazel Fox & Philippa Webb, The Law of State Immunity (2015) at 568; Restatement 3d of the Foreign Relations Law of the U.S., § 464, cmt. i (3rd 1987)). Consent to the visit as one attracting protection appears to mean “consent to the special mission itself” — typically a visit concerning an important issue of relations between the States, creating an analogy to a diplomatic mission (Wood at 67, 69-70; cf. ILC Yearbook, Vol. II (1964) at 210). Moreover, it is not “necessary that the sending and receiving States use the term ‘special mission,’” and “consent may be implied from all the surrounding circumstances” (Wood at 70). Assuming the Iraqi account is correct, Soleimani may well have satisfied both criteria for special mission inviolability because he sought to “deliver a message from Iran” concerning Iraq-mediated negotiation with Saudi Arabia, and Iraq’s prime minister planned to meet him to discuss the negotiations, implying consent to Soleimani’s mission.
The United States itself has on many occasions recognized the customary status of special mission protection. While the scope of special mission protection acknowledged by the United States is not precisely defined, it seems to include at least senior or ministerial-level officials invited on a diplomatic mission.
For instance, in 1978 the State Department recommended—and the district court promptly recognized—special mission immunity for the Prince of Wales because “[u]nder customary rules of international law, recognized and applied in the United States . . . senior officials on special diplomatic missions are immune from the jurisdiction of United States … courts” (Kilroy v. Charles Philip Arthur George Windsor, C 78-291, Suggestion of Immunity by the United States). Likewise, in 2006, the State Department recommended immunity for China’s Minister of Commerce because he “had traveled to the United States pursuant to an invitation of the Executive Branch” to participate in a U.S.-China trade meeting and, therefore, his case “f[e]ll[] well within the widespread consensus that, at a minimum, States are constrained in their ability to exercise jurisdiction . . . over ministerial-level officials invited on a special diplomatic mission.” (Li Weixum v. Bo Xilai, 04-0649, Suggestion of Immunity and Statement of Interest of the United States). According to then-State Department Legal Advisor John Bellinger in 2018, special mission immunity, “grounded in customary international law,” is “necessary to facilitate high level contacts between governments through invitational visits.”
Soleimani may have satisfied even the narrower definition of special mission protection adopted by the United States. He appears to have been invited to Iraq to discuss important matters of Iran-Saudi diplomacy with the Iraqi Prime Minister and, by virtue of his status as a leading Iranian general conducting a high-level foreign relations mission, would seem to at least plausibly qualify as a senior or ministerial-level official.
Assessing Iran’s Potential Claim
If Soleimani was entitled to customary special mission immunity, then—subject to questions about (1) the United States’ duties in relation to an invitee of Iraq, (2) the relationship between the Convention and IHL, and (3) the United States’ awareness of Soleimani’s role discussed below—his killing may have been a crime under art. 2(1)(a) of the Convention, which the United States not only failed to prevent (art. 4(a)) and prosecute (see art. 3(1)(b), art. 7), but itself actively perpetrated.
- The United States’ Duties in Relation to Soleimani
Turning to the first issue, the question arises whether Soleimani was entitled to protection only from attacks by Iraq as the receiving state or also from attacks by third states such as the United States.
On the one hand, the Convention on Special Missions, as expressive of custom, may not impose a duty on the United States to protect Soleimani. Generally, as in the Vienna Convention on Diplomatic Relations, only the receiving or host State must protect a special mission. See, e.g., VCDR Arts. 22, 29; CSM Arts. 25, 29.
At the same time, however, under the Protected Persons Convention, it may not matter whether the United States was obligated to protect Soleimani, so long as he was entitled to international protection vis-à-vis Iraq. That is because Article 1(1)(b) of the Convention defines an internationally protected person as “[a]ny” official “who, at the time when and in the place where a crime against him . . . is committed, is entitled pursuant to international law to special protection.” Nothing on the face of Article 1 requires a protected person to be protected by specific States. Likewise, Article 2 requires States Parties to criminalize any “attack upon . . . an internationally protected person,” without distinction based on the State that owes the protection.
Other provisions may also support a broader reading. Article 3(1)(a)-(b), for example, requires a State Party to establish jurisdiction over its national who committed a crime against an internationally protected person even if the crime was committed outside “the territory of that State.” At least arguably, the relevance of this provision might be called into question if the obligation extended only to crimes committed against persons entitled to international protection by that particular State. The same may be said for Article 4(a), which requires States Parties to take “all practicable measures to prevent preparations” for crimes against an internationally protected person that are planned inside but executed “outside their territories.” It is unclear in what circumstances this provision would be relevant if it applied only to persons entitled to international protection vis-à-vis the particular State required to take all practical measures to prevent preparations for crimes executed abroad.
On the other hand, construing the Protected Persons Convention as covering attacks against any internationally protected person—regardless of which State owes the protection—could imply that attacks on diplomats at embassies around the world potentially implicate the Protected Persons Convention by virtue of the diplomats’ status as individuals entitled to international protection from the host State under the Vienna Convention on Diplomatic Relations (see VCDR Art. 29). Such an expansive obligation may not have been envisioned by the drafters of the Protected Persons Convention.
- The Relationship Between the Protected Persons Convention and IHL
Turning to the second issue, there is a further question of whether the killing of a general necessarily implies the existence of an international armed conflict that might displace the Convention as lex specialis. Analysis of this issue could easily be the subject of a separate post and may feature in any dispute before the ICJ. The Court is currently considering a related question about the relationship between the UN’s privileges and immunities and IHL in the UNRWA request for an advisory opinion. In those proceedings, a significant number of participants, including Ireland (¶ 42), China (¶¶ 66-67), and Brazil (¶ 88), urged the ICJ to conclude that military necessity under IHL cannot override the inviolability of UN premises under the UN Charter and the Convention on the Privileges and Immunities of the United Nations.
In this case, the Court may find relevant the fact that Article 43(2) of the Special Missions Convention states that the privileges and immunities of special missions persist “even in case of armed conflict.” To the extent this provision reflects customary international law, it is incorporated into the definition of an internationally protected person under Article 1(1)(b) of the Protected Persons Convention. The ICJ may also consider the object and purpose of the Protected Persons Convention, accounting inter alia for the preamble’s reference to the “maintenance of international peace” and the importance of averting threats to “normal international relations.”
- The United States’ Awareness of Soleimani’s Role
Turning to the third issue, the ICJ may focus on the extent to which the United States knew of Soleimani’s role in the negotiations. The ILC commentary to an earlier draft of the Convention suggests that the word “intentional” in Article 2 indicates that the offender must be aware of the victim’s protected status. However, it seems possible that the United States did in fact have intelligence about the purpose of Soleimani’s visit to Iraq. According to Iraq’s President, “Donald Trump called him and asked him to mediate with Iran even as the American president was secretly ordering Soleimani’s killing”, and it has been suggested that “Trump helped lure” Soleimani “to a place where he could be killed.”
What next?
The United States’ latest attacks may encourage Iran to seek redress for the Soleimani assassination at the ICJ. Despite having a potentially viable claim, Iran has so far refrained from filing suit, more than one year and a half after it reportedly requested negotiations. There appear to have been no announcements since January 2024, and it seems unlikely that negotiations with the United States have been successful. While it is possible that the parties are in the midst of the six-month period provided in Article 13 for agreement on arbitration, Iran may have also held back to avoid derailing nuclear talks with the United States. The recent conflict could now tip the scales in favor of suit. Lawfare through ICJ litigation may, moreover, offer Iran a way to save face while preserving the ceasefire and avoiding further military escalation—but it is only one of several avenues Iran might pursue, depending on the future of any Iran-US negotiations.
