With Particular Focus on the Philippine Legal and Constitutional Setting

Abstract

The arrest of a former head of state for prosecution before an international criminal court sits at the fault line between two foundational ideas in international law: sovereign equality (and its corollary, immunity) and individual criminal responsibility for atrocity crimes. This article explains (1) what “state immunity” is—and what it is not; (2) the distinct immunities that attach to heads of state and other senior officials; (3) why and how international criminal courts proceed despite immunity doctrines; (4) how arrest and surrender actually work in law; and (5) how these questions map onto Philippine constitutional norms, statutes, and jurisprudential themes (including the incorporation of customary international law, presidential immunity from suit while in office, due process, and the warrant requirement).

I. Why the Topic Matters: Immunity as Procedure, Accountability as Substance

Immunity disputes in atrocity cases are often framed as moral questions (“Can leaders escape justice?”). In law they are usually procedural questions (“Which forum may exercise jurisdiction, and who must cooperate?”). A former head of state may be substantively liable for genocide, crimes against humanity, or war crimes, yet still raise immunities to block proceedings in particular courts—especially foreign domestic courts. Conversely, international criminal courts generally proceed on the principle that official position does not bar jurisdiction.

The practical bottleneck is frequently not the trial, but the arrest and surrender. International courts typically lack their own police forces. They rely on states to locate, arrest, and transfer suspects.

II. “State Immunity” Proper and the Two Official Immunities That People Confuse With It

A. State immunity (sovereign immunity) in the strict sense

State immunity is the rule that one sovereign state is not subject to the jurisdiction of another state’s courts without consent, rooted in sovereign equality and non-intervention. Traditionally it was “absolute,” but most modern practice is “restrictive,” distinguishing between:

Acta jure imperii (sovereign/public acts) → immune; and
Acta jure gestionis (commercial/private acts) → often not immune in civil matters.

In criminal cases, the “defendant” is typically an individual, not the state—yet officials may invoke immunity because their acts are said to be acts of the state, or because their status is protected.

B. Immunity of state officials: two different doctrines

When the person is (or was) a head of state, the relevant doctrines are usually official immunities, not the state’s own immunity as a juridical entity.

Immunity ratione personae (personal immunity)

Attaches to a small class of incumbent senior officials (commonly: head of state, head of government, foreign minister).
Covers all acts (official and private) while in office.
Is temporary; it ends when the official leaves office.
Operates mainly horizontally: it bars the jurisdiction of foreign domestic courts and associated coercive measures (including arrest) while the official is incumbent.

Immunity ratione materiae (functional immunity)

Attaches to official acts performed on behalf of the state.
Can be invoked by former officials because it attaches to the act, not the person.
Is conceptually derivative of the state’s immunity: prosecuting an official for an official act can be treated as indirectly impleading the state.

Key point for former heads of state: personal immunity ends with office; functional immunity may remain only for “official acts.” The central dispute becomes whether international crimes can count as “official acts,” and whether there is a customary “international crimes exception” to functional immunity.

III. Former Heads of State: What Remains Immune After Leaving Office?

A. Personal immunity ends

Once out of office, a former head of state generally loses the procedural shield that blocks foreign domestic jurisdiction regardless of conduct.

B. Functional immunity may remain—but is contested in atrocity cases

For former heads of state, functional immunity could bar foreign domestic proceedings if the charged conduct is legally characterized as an “official act” attributable to the state. This is where atrocity crimes create doctrinal stress:

One line of reasoning treats genocide, crimes against humanity, and war crimes as inherently incompatible with lawful state authority; therefore they should not qualify as protected “official acts.”
Another line of reasoning insists that “official act” means “act performed under color of authority,” even if unlawful; therefore functional immunity may still apply in foreign domestic courts unless there is a clear exception.

In practice:

Many states and courts have been more willing to recognize exceptions for specific treaty crimes (notably torture in post-Pinochet jurisprudence) than to announce a broad, universal exception for all international crimes in all settings.
The law is strongest in the setting of international criminal tribunals, and weakest (most contested) in foreign domestic courts asserting universal jurisdiction.

IV. The International Court Difference: Why Immunity Usually Does Not Block International Criminal Jurisdiction

A. The “vertical” logic

International criminal courts are often described as operating vertically (international community → individual) rather than horizontally (state → state). Many international tribunals proceed on the premise that immunities designed for inter-state comity do not bar an international court exercising criminal jurisdiction.

B. Two legal pathways that neutralize immunity before international courts

Treaty-based waiver/consent Where a state joins a tribunal by treaty, it can be understood to have accepted provisions removing official-capacity defenses and immunities for the tribunal’s jurisdiction and cooperation regime. The Rome Statute’s Article 27 is the paradigmatic example: official capacity does not exempt a person from criminal responsibility, and immunities do not bar the Court.
UN Security Council route (for some tribunals/situations) Where the Security Council acts under Chapter VII to establish or empower a tribunal (or refer a situation), a separate argument arises that member states must comply, potentially overriding certain immunity objections. This pathway is legally and politically contentious depending on the tribunal and the state’s relationship to it.

C. The arrest-and-surrender wrinkle (the hardest part)

Even when the international court may proceed, it still needs a state to arrest and surrender the suspect. Here the immunity issue reappears as a conflict between:

the cooperation obligation owed to the court, and
a state’s other international obligations to respect immunities of another state (especially if the suspect is linked to a non-consenting “third state”).

In the ICC system, this tension is typically discussed through Article 27 (no immunity before the Court) and Article 98 (limits on surrender requests that would force a state to violate immunity obligations owed to a third state absent waiver).

V. Arrest Before an International Court: From Warrant to Surrender

A. The usual sequence

Warrant issued by the international court (or order to appear).
Request for arrest/surrender transmitted to states (often via diplomatic channels).
Domestic execution: local authorities arrest pursuant to domestic legal authority (which may be treaty-implementing legislation, cooperation statutes, or domestic warrants).
Surrender proceedings: many systems provide a judicial hearing to confirm identity, legality of process, and minimum due process requirements.
Transfer to the court’s custody.

B. Arrest vs prosecution as jurisdictional acts

Arrest is an exercise of enforcement jurisdiction. If personal immunity applies (incumbent senior officials in foreign domestic settings), arrest is typically prohibited. For a former head of state, the arrest question turns mainly on:

whether functional immunity applies in the relevant forum, and
whether the relevant international court/cooperation regime displaces it.

VI. Landmark Doctrinal Reference Points (What the World’s Courts Have Said, in Principle)

A few decisions and lines of authority anchor the modern debate:

ICJ, Arrest Warrant (DRC v. Belgium, 2002): incumbent foreign ministers enjoy personal immunity before foreign domestic courts; the ICJ also recognized that such immunity does not mean impunity, noting pathways such as prosecution at home, waiver, or prosecution before certain international criminal tribunals with jurisdiction.
Pinochet (UK House of Lords): widely associated with the idea that a former head of state may not claim immunity for certain international crimes (especially torture) under the relevant treaty framework and the nature of the offense.
ICTY/ICTR practice (e.g., Milosevic indictment): official position does not bar tribunal jurisdiction.
Special Court for Sierra Leone, Charles Taylor: rejected head-of-state immunity before that tribunal.
ICC litigation around sitting heads of state (e.g., Al-Bashir disputes): highlights the Article 27/98 conflict and the contested scope of immunity vis-à-vis the ICC and state cooperation.

The high-level synthesis: international tribunals have been far readier than national courts to deny immunities for international crimes, especially where the tribunal’s jurisdiction is grounded in consent or a Security Council mandate.

VII. Philippine Legal Context: Where Immunity and International Criminal Accountability Fit

A. The Philippine constitutional gateway to international law

The Philippines constitutionalizes receptiveness to international law through the incorporation of “generally accepted principles of international law” as part of the law of the land (the “incorporation clause,” commonly invoked in jurisprudence such as Kuroda v. Jalandoni). This matters because:

head-of-state immunities are largely customary international law; and
Philippine courts frequently treat immunity as intertwined with foreign relations, often deferring to the political branches’ determinations of status and recognition.

B. State immunity doctrine in Philippine jurisprudence (pattern and posture)

Philippine cases on sovereign immunity (including for foreign states and international organizations) typically emphasize:

the non-suitability of states without consent;
the public/private act distinction in some contexts; and
significant judicial deference when the Executive (often via DFA) signals immunity and its scope.

While these cases mostly concern civil jurisdiction, they reflect an institutional posture relevant to any litigation over immunities in a cooperation/arrest dispute: Philippine courts are cautious about adjudicating matters that directly affect foreign relations.

C. Presidential immunity from suit while in office (domestic)

Philippine constitutional practice recognizes presidential immunity from suit during tenure (a jurisprudential doctrine aimed at enabling effective governance). This is distinct from international head-of-state immunity but can affect domestic pathways:

While incumbent: domestic criminal processes against the President are generally barred by this doctrine (separate from impeachment mechanisms and political accountability).
After office: that domestic immunity no longer applies, making former presidents subject to ordinary criminal process.

This matters because a former head of state facing an international court is also, at least in principle, available to domestic criminal process in the Philippines once out of office.

D. The Philippines and international crimes: Republic Act No. 9851

RA 9851 (2009) criminalizes core international crimes in Philippine law (genocide, crimes against humanity, and war crimes) and adopts modern principles such as:

the irrelevance of official capacity (mirroring the international norm that position does not excuse liability), and
command responsibility and related doctrines aligned with international humanitarian and criminal law.

RA 9851 is critical for Philippine context because it supplies a domestic legal basis to prosecute international crimes even when international cooperation becomes contested.

E. The Rome Statute and the Philippine timeline (legal significance)

The Philippines was a State Party to the Rome Statute for a period and later withdrew. The Rome Statute’s withdrawal mechanism is designed so that withdrawal does not automatically erase jurisdiction for crimes allegedly committed while the state was a party, and it preserves certain aspects of ongoing court processes. The practical significance for “arrest of a former head of state” depends on:

what alleged conduct occurred during the State Party period;
whether and when ICC processes were triggered; and
whether Philippine authorities treat cooperation as legally required, legally permitted, or politically rejected post-withdrawal.

(Any analysis of present-day enforceability must distinguish ICC jurisdiction from Philippine cooperation obligations, which do not always move in lockstep.)

F. Domestic due process, arrest, and the warrant requirement

Any arrest physically executed in the Philippines must grapple with constitutional constraints, especially:

the general requirement of a judicial warrant based on probable cause, subject to narrow exceptions; and
due process norms recognized in extradition jurisprudence (Philippine case law has treated extradition as a special proceeding where constitutional rights apply in calibrated form, including jurisprudence on access to information and bail in appropriate circumstances).

Surrender to an international court is not identical to extradition, but Philippine courts may analogize to extradition principles where no tailored implementing statute exists.

VIII. The Core Question Applied: Can a Former Head of State Be Arrested and Surrendered From the Philippines to an International Court?

This question has different answers depending on (1) the forum, (2) the legal basis for the court’s jurisdiction, and (3) the Philippines’ cooperation posture and domestic legal authority.

A. If the Philippines is legally obliged to cooperate (classic State Party scenario)

When a state is fully within a tribunal’s cooperation regime (as with ICC State Parties), the legal theory is straightforward:

Official capacity does not bar the international court’s jurisdiction (Rome Statute Article 27 logic).
The state must arrest and surrender persons sought by the court, including former heads of state, subject to the treaty’s procedures and any domestic implementing framework.

For a former head of state, personal immunity is already gone, so the main residual immunity argument (functional immunity) is typically neutralized by the cooperation regime and the tribunal’s “no immunity” principle.

B. If cooperation is contested or absent (post-withdrawal or non-party posture)

If the Philippines is not (or no longer) bound by a cooperation treaty in the relevant way, arrest and surrender becomes a domestic-law and foreign-relations problem:

Is there domestic legal authority to arrest for surrender? Without a specific cooperation statute, authorities may face the argument that an ICC request alone is not self-executing as a domestic arrest power. Courts could require:

an enabling statute;
a domestic warrant process; or
an executive mechanism lawfully grounded in existing statutes (with constitutional scrutiny).

Would Philippine courts treat the act as extradition-like? If the process resembles extradition, the jurisprudential frame may import:

judicial proceedings,
minimum due process, and
constraints on executive discretion.

How does immunity enter if the person is a former head of state?

Personal immunity: generally not available.
Functional immunity: could be argued in foreign domestic prosecutions; but in a surrender-to-international-court context, its force depends on whether the international court’s jurisdiction and the Philippines’ cooperation obligations displace it.

C. If the request concerns a former head of state of a foreign country present in the Philippines

This is where classic “immunity law” can become decisive even for a former leader:

If a foreign former head of state is sought by an international tribunal, the Philippines must ask:
1. Is the Philippines bound to cooperate with that tribunal?
2. Does the tribunal’s framework neutralize immunities?
3. Does Philippine domestic law authorize arrest and surrender?
4. Are there separate diplomatic constraints (recognition, relations, safety, reciprocal treatment)?

If the person were still incumbent, personal immunity would be a much harder barrier. Because the topic is a former head of state, the most serious legal fights shift from “immunity” to “domestic authority and procedure.”

IX. Article 27 vs Article 98 Logic (ICC Model): The Doctrinal Engine Room

Even though the Philippines’ current formal relationship with the ICC is complex, the ICC framework remains the most developed model for immunity disputes.

Article 27 expresses the internal rule of the Court: official capacity is irrelevant; immunities do not bar the Court from exercising jurisdiction.
Article 98 addresses the external problem of cooperation: the Court should not put a requested state in the position of breaching its obligations to respect the immunities of a third state, unless that third state waives immunity.

For former heads of state, Article 98 issues generally weaken (because personal immunity is gone), but do not always disappear if functional immunity is invoked and treated as an obligation owed to the foreign state.

X. Philippine-Forward Scenarios and Legal Pathways

Scenario 1: A former Philippine President sought by an international court for crimes committed during a period of treaty engagement

Key questions:

Did alleged crimes fall within the relevant temporal jurisdiction?
Is the Philippines legally obliged to cooperate or merely permitted?
Is there a domestic legal pathway to effect arrest/surrender consistent with the warrant requirement and due process?

Likely Philippine legal battleground: not “personal immunity,” but separation of powers, treaty/withdrawal effects, and domestic implementing authority.

Scenario 2: The Philippines prosecutes domestically under RA 9851 instead of surrendering

RA 9851 supplies the framework for domestic prosecution of international crimes. This route is especially salient where:

surrender is politically rejected;
cooperation obligations are disputed; or
domestic courts insist on clearer legislative authorization for surrender.

This also ties into the international principle of complementarity (international courts often treat genuine domestic proceedings as a reason to defer).

Scenario 3: A foreign former head of state is found in the Philippines and sought by an international tribunal

Here, Philippine authorities must manage:

the presence requirement (often essential in practice),
domestic arrest authority, and
the diplomatic implications of executing an international warrant.

Immunity disputes are less about personal immunity and more about whether functional immunity survives in the specific cooperation setting—and whether Philippine courts will treat international crimes as beyond the protective scope of “official acts.”

XI. Practical and Policy Observations (Without Losing the Law)

Immunity is forum-sensitive. A former head of state may be hard to prosecute in a foreign domestic court (functional immunity debates), yet still prosecutable before an international tribunal (no-immunity principle).
Arrest depends on domestic machinery. Treaties create international obligations, but actual arrest is executed through local legal authority. Where implementing statutes are thin, constitutional litigation becomes likely.
In the Philippines, constitutional rights and judicial review matter. Arrest and surrender processes that are perceived to bypass warrants, hearings, or minimum due process protections will invite intense scrutiny.
The “state immunity” label is often misleading. Most disputes are really about official immunities and cooperation law, not about suing a state as a defendant.

XII. Conclusion

The arrest of a former head of state before an international court is best understood as the intersection of three legal systems operating at once: customary immunity rules, international criminal tribunal law (often rejecting immunities), and domestic constitutional procedure (governing arrest, detention, and transfer). In the Philippine context, the decisive issues are rarely about lingering personal immunity—because former heads of state generally do not have it—but about the legal architecture for cooperation or surrender (treaty effects, implementing authority, executive action, and judicially enforceable rights). The modern direction of international criminal law is clear in principle—official position does not bar accountability—but the real-world effectiveness of that principle depends on whether domestic legal systems, including the Philippines, can lawfully convert international requests into constitutional arrests and transfers.