In July 2024, the US Supreme Court held, in a 6-3 ruling, that former President Donald Trump enjoys absolute immunity for acts he committed within his constitutional powers as President, even though they were unlawful under US law. The decision has sparked debate over potential implications for rogue presidents who may wish to subvert the law (here), and US foreign policy (here, here, here). Justice Sotomayor, in her dissent, observed that this “new official-acts immunity now ‘lies about like a loaded weapon’ for any President that wishes to place his own interests, his own political survival, or his own financial gain, above the interests of the Nation”.
The Supreme Court conferred immunity under domestic law. But as the arrest warrants against President Putin and Prime Minister Netanyahu demonstrate, Heads of State are in the spotlight of international law just as much as domestic law. In fact, it could be said that their role engages international law more than any other official in government. Therefore, in this post, we explore the US Supreme Court’s ruling from the viewpoint of international law.
The Supreme Court’s Ruling
In August 2023, a grand jury issued an indictment accusing former President Trump of five streams of activity occurring during and after the November 2020 election. It alleged that Trump and his co-conspirators:
1. Knowingly used false claims of election fraud to compel election officials to change electoral votes for Biden to Trump;
2. Organised fraudulent slates of electors in seven targeted states, which were sent to be counted at the certification proceeding on 6 January 2021;
3. Attempted to use the Justice Department to conduct sham election investigations and send a letter to some states that falsely claimed that the Justice Department had identified concerns that could have impacted the election outcome;
4. Attempted to persuade Vice President Pence to fraudulently alter election results, and then repeated knowingly false claims of election fraud to gather supporters;
5. Exploited the January 6th disruption by redoubling efforts to levy claims of election fraud and convince Members of Congress to further delay the certification.
The Supreme Court held that Trump cannot be prosecuted for actions within his constitutional powers as president. Chief Justice Roberts, writing for the majority, confirmed that the President is absolutely immune from criminal prosecution for acts within his exclusive authority:
“At a minimum, the President must … be immune from prosecution for an official act unless the Government can show that applying a criminal prohibition to that act would pose no ‘dangers of intrusion on the authority and functions of the Executive Branch’.”
This immunity does not extend to unofficial conduct:
“As for a President’s unofficial acts, there is no immunity… Although Presidential immunity is required for official actions to ensure that the Presidents decisionmaking is not distorted by the threat of future litigation stemming from those actions, that concern does not support immunity for unofficial conduct.”
The case was ultimately remanded back to the presiding US district judge to determine whether Trump’s conduct fell within a President’s official acts, though the Court pre-emptively determined that some of Trump’s acts, such as his interactions with Justice Department officials, were official acts. However, since President Trump’s 2024 re-election, almost all of the charges have been dropped.
The US is not the only State that provides immunity to its Head of State under constitutional rules, and a survey of State practice from African, Asian, European, and Latin American States shows that the immunity of Heads of State under domestic law is of growing importance. Notably, there is an emerging practice of limiting the immunity of sitting heads of states, according to the principle that no person is above the law (see here, here, here, and here). The Supreme Court’s judgment has been criticised for its incompatibility with this principle.
The distinction between official and unofficial conduct
International law extends to former heads of states immunity from criminal jurisdiction for certain conduct, where doing so is necessary to “preserve the integrity of the activities of the foreign state” during the period when the Head of State was in control. (Pinochet (No 3), 200). This functional immunity protects the former Head of State from being prosecuted for acts in an official capacity, such as military activities, the exercise of public power, or legislative acts (Fox & Webb). Functional immunity does not bar proceedings in respect of “acts committed during [the] period of office in a private capacity” (ICJ Arrest Warrant, para. 61).
The UK House of Lords confirmed in Pinochet (No 3) that the critical question for determining whether an act is performed in an official capacity is “whether the conduct was engaged in under colour of or in ostensible exercise of the head of state’s public authority”. Illegal conduct is not automatically excluded from the scope of official immunity. Instead, as the ILC confirmed in the current version of its draft articles on immunities of State officials, an “act performed in an official capacity” is “any act performed by a State official in the exercise of State authority”. Such acts will share a “direct connection between the exercise of State functions and powers, found where an official is acting “in the exercise of their functions and in the interests of the State”.
The division between conduct in an official or private capacity also arises in relation to State responsibility, under the rules of attribution applicable to State organs. For example, in relation to the rule that the State will be responsible for the conduct of an organ under international law, the ILC has clarified that the rule extends to “organs of government of whatever kind of classification”, citing an arbitral decision that held: “a State is responsible for the acts of its rulers, whether they belong to the legislative, executive, or judicial department of the Government, so long as the acts are done in their official capacity” (Salvador Commercial Company case, p. 477).
The Supreme Court’s decision also adopts an official/unofficial dichotomy, but the analysis does not mirror that of international law. The Supreme Court decided that the category of “official conduct”—for which former presidents enjoy absolute immunity—contains two sub-divisions: (i) acts falling within a president’s “core” functions, and (ii) other acts falling within the “outer permitter” of presidential authority. The former are functions unfettered by legal restrictions, such as firing employees or issuing pardons, which the president may do on his or her own discretion, and which are absolutely immune. Conduct falling within the latter “outer perimeter” of the president’s functions can be harder to categorise as official or unofficial, and in these cases, the president is “presumptively immune” unless the prosecution can demonstrate that the relevant act was unofficial or there would be no danger of a “distracting intrusion” on his or her attention.
This tripartite division of immune/presumptively immune/non-immune conduct does not exist in international law—courts have found that there is no “grey” area between official and unofficial conduct. For example, in Jones v. Saudi Arabia, Lord Hoffmann cited to a case in which a US deputy constable, who held a private grudge against the Mexican consul, had assaulted him on two separate occasions: first, on a street on a Sunday night, while on a private outing. This was held to be an act in his private capacity. On the second occasion, the constable, while on duty, boarded a car in which the consul was traveling, showed his badge, beat him up and took him to jail. Although this seemed to be a “private act of revenge”, “the act as a whole [could] only be considered the act of an official” and was therefore immune.
The Supreme Court’s decision, though based loosely on the US Constitution, had little textual grounding. Nowhere in the Constitution does it discuss presidential immunity. Instead, the judgment applied presidential immunity “under [the] constitutional structure of separated powers”, considering the “nature of Presidential power”, which “requires that a former President have some immunity from criminal prosecution for official acts during his tenure in office”. Nor does the Constitution refer to the tripartite distinction (immune/presumptively immune/non-immune) used by the Supreme Court . This distinction was based on previous decisions of the Court and the design of the Presidency within the separation of powers doctrine.
By contrast, under international law, the scope of Head of State immunity is formed through “widespread and representative” State practice and opinio juris. The limitations on Head of State immunity are necessarily supported by, at the very least, an emerging practice and in other areas by longstanding, consistent practice.
In terms of the Supreme Court’s categorisation of Trump’s conduct into the groups of immune, presumptively immune, and non-immune, the majority concluded that his alleged attempts to compel the Department of Justice to launch criminal investigations into non-existent election frauds fell within the “core” constitutional duty to “take care that the laws be faithfully executed”, and were therefore absolutely immune from prosecution. The allegations that Trump tried to swing states to falsify their election returns to the Senate and convince the Vice President to reject the election results of certain states did not concern “core functions:, so were only presumptively immune. However, discussing such matters with state authorities and the Vice President in particular may be a presidential function. Trump’s threatened removal of the acting Attorney General formed part of the executive branch’s function of “investigative and prosecutorial decision-making”, such that it fell within his conclusive and preclusive presidential authority. As for Trump’s conduct on January 6th 2021, when he allegedly urged his supporters to go to the Capitol and place pressure on the Vice President, the Court found that the president “possesses extraordinary power to speak to his fellow citizens”, and if Trump was tweeting and speaking as president, then what he said was also immune.
By contrast, under international law, the ILC has confirmed that “as a rule, acts performed by officials purely for their own benefit and in their own interest cannot be considered as acts performed in an official capacity”. It would be difficult to argue that Trump’s alleged efforts to overturn the election results were taken within the interests of the State.
Some argue that committing international crimes can never be within a State’s proper functions. For example, the Paris Cour d’Appel held in Assad that the use of chemical weapons is not an official function as it violated a peremptory norm of international law (this decision is on appeal). Members of the ICJ have also noted that “serious international crimes cannot be regarded as official acts because they are neither normal State functions nor functions that a State alone (in contrast to the individual) can perform” (ICJ Arrest Warrant, Joint Separate Opinion of Judges Higgins, Koojimans, and Buergenthal, para. 85).
Moreover, under international law, “the court must consider the whole context in which the claim against [the state official] is made” (I Congreso del Partido). As Lord Sumption has noted (here, writing extrajudicially), the Supreme Court’s approach was “to look separately at each of the things Trump is alleged to have done to further it”. If the Supreme Court had taken a holistic view of Trump’s conduct, it may well have reached the conclusion that there were self-interested activities in his personal capacity.
Implications for international law
The decision of the Supreme Court establishes that a president cannot be prosecuted of, for example, pocketing funds from a foreign government, which opens up potential for a foreign government to bribe their way out of state sanctions, or an embargo, or diplomatic trouble arising from, for example, murdering a journalist working for a US newspaper (see here).
But the decision also has wider implications. For example, one issue is where the Supreme Court’s decision now places US law when considered from the international perspective. The Supreme Court appears to have ruled that, even if a US president orders an act of torture to take place on US territory, or where the US has control of a territory, that president will enjoy immunity under Constitutional law before US Courts, but under the Pinochet (No 3) decision and subsequent developments in relation to the exercise of universal jurisdiction, he will not enjoy immunity in foreign courts (see here).
Moreover, functional immunity is a customary rule, formed through State practice and opinio juris. As the consequences of the Supreme Court’s decision are explored, there are various states around the world with leaders who may wish to adopt the same approach (see here). It will be for the international community, including those within the United States who believe in accountability for those who occupy the most important office, to unload the gun of unchecked power.
