Pacta sunt servanda.
Practice area · VII
Immunities, diplomatic protection and sovereign defence
Immunity is a field of forces. Behind the technique lie power relations between States, leaders and courts. Defending it, invoking it or waiving it is not first and foremost a matter of pleading: it is a matter of building a position, characterising the act, choosing the forum, choosing the moment and anticipating waiver. It is an architecture, not mere advocacy.
A leader, Head of State, minister, diplomatic agent or special envoy arrested, prosecuted or threatened with extradition abroad; an embassy or consulate violated, an agent or a person sheltering there harmed; a State aircraft, embassy account or sovereign asset seized or confiscated; a former president targeted by foreign criminal proceedings; an injured national seeking espousal by his or her State: immunities are not an abstract privilege, but a procedural line of defence that must be characterised before any step is taken on the merits.
Leaders, ministers, agents and envoys
Personal, functional and criminal immunity; arrest, extradition
Inviolability and sovereign assets
Embassies, consulates, agents, State aircraft, accounts, assets
Diplomatic protection and inter-State disputes
Espousal of claims, assessments, expert opinions, overall strategy
Immunity is not a wall. It is a regime. Whoever masters its exceptions, its waivers and its thresholds holds the position.
Identify your situation
Immunities, assets, leaders, missions: identify your situation
Six points of entry. The firm handles each in isolation, or several together under a single strategy.
A leader, a Head of State or a special envoy is targeted abroad
Arrest, criminal prosecution, warrant or threat of extradition directed at a serving leader, a former official or an envoy on official mission. Objective: to establish personal or functional immunity and secure the person.
A minister, a diplomatic agent or a consul is personally targeted
A serving minister, a member of a government, a diplomatic agent or a consul is prosecuted, detained, summoned or declared persona non grata abroad. Objective: to assert the personal or functional immunity attached to the office and to the mission.
An embassy or a consulate is violated or threatened
Entry into premises, interference with archives, with an agent or with a person sheltering within a mission. Objective: to assert inviolability and respond solely through the avenues provided for by law.
A sovereign asset is seized or confiscated
State aircraft, embassy account, central bank asset or sovereign property subject to seizure or confiscation. Objective: to secure recognition of immunity from execution and of the protected nature of the property, or to obtain release of the asset.
A national or a company seeks diplomatic protection
An individual or a company injured abroad seeks to have the claim espoused by the State of nationality. Objective: to establish nationality, continuity and exhaustion of local remedies as the basis for espousal.
A State must invoke or defend its immunity
Foreign proceedings are brought against a State or one of its emanations, or a creditor seeks to enforce against it. Objective: to invoke immunity from jurisdiction or from execution, characterise the act and prevent any waiver.
Characterising immunity
Immunity is invoked, waived or defended on its characterisation, never on the obvious.
Immunity is not a privilege: it is a rule of law that must be argued.
Strategic diagnosis
Warning signs and aggravating factors
Certain indicators show that the situation no longer calls for ordinary handling, but for a crisis architecture. These signals are not sufficient to characterise the case in law; they warrant a rapid, confidential and structured mapping.
Warning signs
- Seizure or enforcement measure directed at the property of a State, an embassy or a central bank.
- Foreign proceedings directed at a leader, a former leader, a diplomat or a special envoy.
- Confusion between immunity from jurisdiction and immunity from execution.
- Public assets used or presented as commercial.
- Request for cooperation, extradition or INTERPOL notice directed at a person who may be protected.
- Breach of the inviolability of a mission, of archives or of diplomatic premises.
Aggravating factors
- Late characterisation of the actual use of the assets.
- Absence of evidence as to the sovereign, diplomatic or commercial nature of the property.
- Conflation of diplomatic protection, personal immunity, functional immunity and criminal defence.
- Enforcement strategy launched without a prior analysis of immunities.
- Public communication on a sovereign dispute before the legal position has been stabilised.
Mistakes to avoid
- Assuming that an award or a judgment automatically makes State property attachable.
- Forgetting that immunity from execution is distinct from, and more robust than, immunity from jurisdiction.
- Overstating the exceptions to immunity for international crimes when the law remains unsettled.
- Handling a special mission without verifying the consent of the receiving State and the official mandate.
- Confusing diplomatic asylum, inviolability of premises and diplomatic protection.
Situation 1 · Leaders, Heads of State and envoys
Leaders, envoys and personal immunities
Heads of State, ministers, diplomatic agents, special envoys and former officials: who enjoys which immunity, and how far it extends.
Personal immunity and functional immunity
Immunity ratione personae, which attaches to the office and is absolute for the duration of the term, is distinct from immunity ratione materiae, which attaches to acts performed in an official capacity and survives the end of office. This distinction governs the defence of a leader or an agent.
The troika and former leaders
A serving Head of State, Head of Government or Minister for Foreign Affairs enjoys full personal immunity before foreign criminal courts, without distinction between official and private acts, as the International Court of Justice held in its Judgment of 14 February 2002 in the case concerning the Arrest Warrant of 11 April 2000 (DRC v. Belgium). This immunity ends with the term of office; only functional immunity then remains.
Diplomats, consuls, envoys and special missions
Diplomatic and consular agents are governed by the Vienna Conventions of 1961 and 1963; the immunity of special missions and of certain official envoys, codified by the 1969 Convention and recognised, depending on the circumstances, under customary international law, rests on the consent of the receiving State, the official character of the mission and the mandate actually exercised. The characterisation of status determines the protection.
Arrest, surrender and safety abroad
When a leader, a former official or an envoy is arrested, detained or threatened with surrender outside his or her own State, immunity must be argued as a matter of urgency, in conjunction with extradition law and the principle of non-refoulement. Securing the person comes first; then comes the challenge to the very basis of the coercion.
International crimes: a shifting front
The functional immunity of former leaders in respect of crimes under international law, namely genocide, crimes against humanity, war crimes, torture and enforced disappearance, is under consideration by the International Law Commission: draft articles adopted on first reading in 2022, with second-reading work carried out in 2026, the Drafting Committee having worked on a set of seventeen draft articles submitted to the Commission, including a draft article 7 on exceptions. The law is not settled; prudence requires distinguishing what is established from what remains contested.
For an exposed leader, the question is not innocence or guilt: it is status, forum and timing.
Situation 2 · Diplomatic inviolability
Embassies, consulates and inviolability
Premises, archives, agents, persons sheltering within a mission: the regime of diplomatic inviolability and the responses it dictates.
A self-contained regime
Diplomatic law is one of the oldest and most stable branches of international law. In its Judgment of 24 May 1980 in the case concerning United States Diplomatic and Consular Staff in Tehran (United States v. Iran), the International Court of Justice described it as a self-contained regime: faced with an abuse, the receiving State may not violate the inviolability of the mission, but has only the responses provided for, including the declaration of persona non grata and the severance of relations.
Premises, archives, agents
The inviolability of the premises of the mission and of its agents is laid down in Articles 22, 29, 31 and 32 of the 1961 Vienna Convention. The Judgment of 11 December 2020 in Immunities and Criminal Proceedings (Equatorial Guinea v. France) clarified the conditions under which a building acquires the status of premises of a mission, the Court finding that the building at issue had not acquired it.
A live issue
The proceedings in Mexico v. Ecuador, instituted after Ecuadorian forces entered the Mexican Embassy in Quito on 5 April 2024, illustrate the tension between the inviolability guaranteed by Article 22 and the duty to respect local laws under Article 41. By Order of 23 May 2024, the Court found that the circumstances did not require the indication of provisional measures; the case remains pending on the merits.
Inviolability is not offset by a good cause. It is upheld, or it is violated.
Situation 3 · Sovereign assets and enforcement
Sovereign assets and immunity from execution
Embassy accounts, State aircraft, central bank assets: what may be seized, and what may not.
Jurisdiction and execution, two regimes
Obtaining a judgment or an award against a State does not guarantee recovery. Immunity from execution, more robust still than immunity from jurisdiction, bars measures of constraint against property. The 2004 Convention protects immunity from execution both before and after judgment, as reflected in its Articles 18 and 19, and permits post-judgment constraint only against property specifically in use for commercial purposes.
Specially protected property
Certain categories of property are immune from attachment, as reflected in Article 21 of the 2004 Convention: property of diplomatic missions and embassy accounts, military property, property of a central bank or monetary authority, and cultural heritage property. The defence of sovereign assets rests on the characterisation of such property.
Waiver and arbitration clause
A waiver of immunity from execution must be assessed with rigour; its scope depends on its wording and on the forum. Conversely, a poorly drafted arbitration clause or contractual waiver may open up unforeseen exposure.
Enforcement of arbitral awards
For the award creditor, the strategy consists in establishing the commercial use of the property targeted and the required link with the debtor entity. For the State, it consists in demonstrating the sovereign nature of the assets. This is litigation over assets, accounts and characterisation, in which documentary precision prevails over principle.
Immunity from execution is the last line. It is often there, over the nature of the property, that recovery is won or lost.
Situation 4 · Diplomatic protection
Diplomatic protection
When and how the State of nationality may espouse the claim of a national or a company injured abroad.
A discretionary act of the State
Diplomatic protection remains an act of the State, which it is under no obligation to exercise. Codified in the 2006 Articles of the International Law Commission, in the wake of Barcelona Traction (1970), it requires the nationality of the claim, the continuity of that nationality and the exhaustion of local remedies.
Building the case for espousal
The firm's role is to bring together, in advance, the conditions that make espousal legally possible and politically defensible, and to coordinate the approach with domestic remedies and human rights mechanisms. The Ahmadou Sadio Diallo case (Guinea v. DRC), in which the Judgment on compensation of 19 June 2012 fixed the reparation due to the applicant State, illustrates its contemporary reach.
Diplomatic protection is not claimed: it is prepared, piece by piece, until espousal becomes defensible.
Situation 5 · The State and its immunity
Defending the immunity of an exposed State
Invoking the immunity from jurisdiction and from execution of a State or an emanation exposed before a foreign court.
Invoking immunity without losing it
When foreign proceedings are brought against a State, an emanation or a State-owned enterprise, immunity from jurisdiction is raised before any argument on the merits, on the basis of sovereign equality (par in parem non habet imperium). An appearance on the merits or a misread waiver clause may amount to a waiver: the defence is decided from the first step.
Characterising the act and preserving immunity from execution
The restrictive doctrine covers only sovereign acts (jure imperii), to the exclusion of acts of a private or commercial nature (jure gestionis). A waiver of immunity from jurisdiction does not entail a waiver of immunity from execution: the two regimes remain distinct, and the protection of assets is prepared separately.
Before a foreign court, immunity is not argued after the fact: it is raised at the outset, or it is lost.
Risk patterns
Recurring configurations of coercion
Identifiable situations, in which the initial characterisation and the order of the steps taken decide the outcome.
Arrest or surrender of a leader or an envoy
A serving leader, a former official or an envoy holding an official mandate is arrested, detained or threatened with surrender abroad. Personal or special mission immunity must be established as a matter of urgency, before any other step.
Breach of the inviolability of an embassy or a consulate
Entry into premises, interference with archives, with an agent or with a person sheltering within a mission. The response must proceed solely through the avenues provided for by law, and not through an unlawful countermeasure.
Confiscation or seizure of a sovereign asset
A State aircraft, an embassy account, a central bank asset or sovereign property is seized or confiscated without any analysis of its nature. The characterisation of the property determines its release.
Criminal prosecution of a former leader abroad
Foreign criminal proceedings target a former Head of State or official, mixing political stakes with ordinary criminal characterisation. Residual functional immunity and the scope of the exceptions must be characterised without delay.
Involuntary waiver of an immunity
An appearance on the merits, a poorly drafted contractual or arbitration clause, or imprudent correspondence amounts to a waiver of immunity from jurisdiction or from execution, without the State having intended it.
State or emanation exposed before a foreign court
Proceedings or an enforcement measure target a State, a State-owned enterprise or a sovereign wealth fund. Immunity from jurisdiction or from execution must be invoked before any argument on the merits.
What the firm puts into practice
The method
A sequence, from characterisation to enforcement, conducted case by case.
01
Immediate characterisation
Identify the applicable regime: immunity from jurisdiction or from execution, personal or functional, diplomatic, consular or special mission immunity, and the relevant exceptions.
02
Audit of documents, clauses and waivers
Examine the procedural documents, the contractual and arbitration clauses, the applicable treaty and the correspondence, in order to prevent any involuntary waiver and secure the position.
03
Forum strategy
Coordinate domestic courts, arbitration, diplomatic channels, inter-State proceedings, independent expert opinion and overall public international law strategy, in the right order and to the intended effect.
04
Defending or contesting assets
Classify the property targeted, establish its sovereign nature or its commercial use, and protect the assets at issue or, for the creditor, reach them.
05
Defence of leaders, agents and missions
Characterise personal or functional immunity, secure travel and official acts, and respond to breaches of inviolability through the avenues provided for.
06
Diplomatic protection and inter-State routes
Build the espousal file, establish nationality, continuity and exhaustion of remedies, and prepare, where appropriate, the inter-State or advisory route.
Expert work and strategy
Expert opinions, assessments and overall strategy
Beyond the litigation engagement, the services of an expert architect of public international law.
An offering distinct from the litigation engagement
The firm may act without necessarily being lead counsel in litigation.
Deliverables
Public international law studies, risk assessments, independent expert opinions, strategic memoranda, jurisdictional analyses, mapping of remedies, notes on the immunity of a State or a representative, architectures for inter-State disputes and private legal diplomacy.
Recipients
This work may be intended for a State, a foreign ministry, a litigation team, a domestic firm or a strategic adviser.
The firm's value does not lie in promising a hearing: it lies in building the legal architecture of a position, in advance and behind the scenes of the case.
Effects obtained or sought
Anonymised results and effects sought
The firm does not publish case studies that name its clients. The confidentiality of engagements is a non-negotiable condition. The results below are presented by category of effect obtained or sought in matters of immunities, diplomatic protection and sovereign defence.
Immunity raised before the merits
Immunity from jurisdiction pleaded before any defence on the merits, and before any risk of waiver by appearance.
Attachment blocked or lifted
Interim or enforcement measures against sovereign assets blocked or lifted, through the characterisation of the property concerned.
Specially protected assets
Protection of diplomatic property, central bank assets and other property specially protected against measures of constraint.
Securing a leader or an envoy
Securing the travel, official visit or position of a leader, official or envoy exposed abroad.
Diplomatic inviolability upheld
Response to violations of premises, archives or an official, solely through the avenues provided by law.
Espousal and diplomatic protection
Structured diplomatic protection file, ready to support espousal of the claim by the State of nationality.
Expert reports and assessments
Confidential studies on the immunity of a State, a public entity, a sovereign asset or a representative, to structure a defence before domestic courts, in arbitration, through diplomatic channels or between States.
Inter-State disputes and overall strategy
Strategic memoranda, procedural mapping, jurisdictional analyses and scenarios for disputes between States, without necessarily assuming lead representation.
A selection of configurations handled
By category and without any identifying element. They illustrate the nature of the cases, not their outcome, and constitute neither a promise nor a guarantee of results.
The legal framework relied upon
Texts, case law and scholarship
01
Treaty texts
Charter of the United Nations (sovereign equality); Vienna Convention on Diplomatic Relations (1961), Articles 22, 29, 31 and 32; Vienna Convention on Consular Relations (1963); United Nations Convention on Jurisdictional Immunities of States and Their Property (2004), Articles 5, 10, 18, 19 and 21, a codification instrument not yet in force (as at 24 June 2026, twenty-five parties; thirty instruments required, Article 30); European Convention on State Immunity, known as the Basel Convention (1972); Convention on Special Missions (1969); Convention on the Prevention and Punishment of Crimes against Internationally Protected Persons (1973). Sources: United Nations Treaty Collection.
02
Case law
United States Diplomatic and Consular Staff in Tehran (United States v. Iran), 24 May 1980; Arrest Warrant of 11 April 2000 (DRC v. Belgium), 14 February 2002; Certain Questions of Mutual Assistance in Criminal Matters (Djibouti v. France), 4 June 2008; Jurisdictional Immunities of the State (Germany v. Italy; Greece intervening), 3 February 2012; Ahmadou Sadio Diallo (Guinea v. DRC), judgments of 2010 and 19 June 2012; Immunities and Criminal Proceedings (Equatorial Guinea v. France), 11 December 2020; Embassy of Mexico in Quito (Mexico v. Ecuador), order of 23 May 2024, case pending; Barcelona Traction (1970); ex parte Pinochet (No. 3), House of Lords, 1999. Sources: International Court of Justice.
03
Codification work
International Law Commission Articles on Diplomatic Protection (2006); draft articles on the immunity of State officials from foreign criminal jurisdiction, first reading in 2022, second reading conducted in 2026, the Drafting Committee having worked on a set of seventeen draft articles submitted to the Commission, draft Article 7 on exceptions for crimes under international law. Sources: International Law Commission.
04
Scholarship
Hazel Fox and Philippa Webb, The Law of State Immunity (Oxford University Press); Eileen Denza, Diplomatic Law (Oxford University Press); Jean Salmon, Manuel de droit diplomatique (Bruylant); Satow's Diplomatic Practice (Oxford University Press); Michael Wood and Andrew Sanger (eds), Immunities of Special Missions (Brill, 2019); Dapo Akande and Sangeeta Shah, Immunities of State Officials, International Crimes, and Foreign Domestic Courts (European Journal of International Law, 2010).
International Court of JusticeInternational Law CommissionUnited Nations Treaty Collection
Where an immunity is at stake, the first procedural error can lock the case in place. An appearance on the merits, a misread waiver clause, an attachment levied on protected property or an approximate characterisation of an official's status can shift the entire balance of power. The analysis phase determines the outcome.
Frequently asked questions
Immunities, execution, leaders: the essentials
Preparing the first contact
Useful documents for an initial analysis
There is no need to send a complete file at the first contact. Certain elements make it possible to characterise the situation quickly.
- Originating process
- Court decision or arbitral award
- Arbitration clause
- Any waiver clause
- Documents relating to the property targeted
- Banking or asset records
- Status of the entity or official capacity of the person concerned
- Note verbale or diplomatic correspondence
- History of domestic remedies and proceedings
- Decisions already handed down
- Known critical deadlines
- Local counsel already instructed
The purpose of the first exchange is to assess the urgency and the relevance of an intervention. It does not, in itself, constitute a full opinion on the prospects of success.
Modes of intervention
Six ways of engaging the firm
For the party concerned, for counsel already instructed, for arbitral or judicial proceedings, by way of prevention, or for the firm outsourcing expert work.
01
Direct advice and representation
Full engagement for the State, sovereign entity, leader, official or creditor: characterisation, forum strategy, written submissions, emergency measures and conduct of the proceedings through to their conclusion.
02
Co-counsel with a domestic firm
Alongside counsel already instructed, before domestic courts, in arbitration, in an inter-State dispute or before a specialised chamber, without displacing lead counsel.
03
Confidential expert support
Opinions, consultation, strategy, drafting of grounds and public international law memoranda, in support of a State, a foreign ministry, a fund, a legal department or a fellow practitioner, the referring firm retaining attribution.
04
Expert witness and professional opinion
Public international law opinion produced for arbitral or judicial proceedings, on the immunity of a State, a sovereign asset or a representative, or on a question of diplomatic protection.
05
Targeted engagement on a strategic front
Intervention confined to a specific front of the case: characterisation of an act, audit of a waiver clause, jurisdictional memorandum, or architecture of an inter-State dispute.
06
Monitoring, anticipation and prevention
Preventive arrangements: mapping of the exposure of a State, a leader, an official or an asset, risk monitoring and legal architecture put in place before a crisis arises.
Engagements led by Professor Ludovic Hennebel, Avocat à la Cour (Aix-en-Provence Bar), Professor of International Law at Aix-Marseille University and elected Expert of the United Nations Committee on Economic, Social and Cultural Rights.
Related practice areas
Continue within the firm's ecosystem
Immunities interact with sanctions, investment arbitration, human rights and lawfare. Related Praxis resources and Corpus entries.
Contact by profile
Find the right point of entry
Depending on your profile, an initial confidential orientation discussion, without mutual commitment.
States and sovereign entities
Proceedings served abroad, challenge to immunity, inter-State or diplomatic dimension.
State-owned enterprises and sovereign wealth funds
Action against a State emanation, characterisation of the act, exposure of assets.
Award creditors
Enforcement of an award or judgment against a State, identification of attachable property.
Heads of State, leaders, envoys and former leaders
Arrest, prosecution, warrant, threat of extradition, criminal immunity, travel security.
Diplomatic missions, consuls, officials and envoys
Breach of inviolability, challenge to status, special mission.
Lawyers, correspondents and foreign firms
Immunities aspect of a case, co-counsel and confidential expert support.
Where an immunity is at stake, the task is not to answer proceedings but to regain control of the balance of power: through characterisation, forum and timing.
An immunity to raise, to lift or to defend?
State, leader, official, national, creditor or correspondent firm: the window for action is narrow and the initial characterisation determines everything. Initial confidential orientation discussion, without mutual commitment. In French, English and Spanish.