Jurisdiction of the ICC, ICTY/ ICTR and domestic courts

1. International Criminal Courts
1.1. Why is the prosecution of individuals for crimes against humanity, deemed controversial?
The prosecution of war criminals by the Nuremberg Tribunal (IMT) made clear that the category of "crimes against humanity" (the category of "violation of peace" alike) would interfere with a state's sovereignty with respect to domestic jurisdiction and governmental activities, such as the waging of war. Also, the category of "crimes against humanity" would be contary to the universal principle "nullum crimen sine lege" (Art. 22 Rome), as no such category of crimes was recognized before the IMT was set up.
The first international case to give rise to a wide recognition of individual responsibility for war crimes, whether they were committed on an international scale or within the boundaries of a state, was the Tadic case of the ICTY.

1.2. How is the jurisdiction of the ICC defined?
The jurisdiction ratione personae of the ICC is limited to individuals. The Court has jurisdiction over natural persons pursuant to the Statute, according to Article 25 of the Rome Statute. The International Criminal Court was established by the Rome Statute. The jurisdiction of the ICC is based on the principle of complementarity, as Article 1 of the Rome Statute reads. The primacy of domestic courts with respect to exercising jurisdiction over crimes, implies that the ICC only has jurisdiction when a State is unwilling or unable genuinely to carry out the investigation or prosecution, as Art. 17 ( Issues of admissibility) of the Rome Statute makes clear.

1.2.1. material jurisdiction
The substantive component of international criminal law, making up the material jurisdiction, consists of four core crimes, as Article 5 of Rome puts it: "The jurisdiction shall be limited to the most serious crimes of concern to the community as a whole. The Court has jurisdiction with respect to: the crime of genocide, crimes against humanity, war crimes and the crime of aggression".

1.2.2. core crimes
Conviction of the individual for committing core crimes, requires the fulfilment of actus reus and mens rea. With respect to actus reus, the crimes of genocide, war crimes and crimes against humanity are covered by articles 6-8 of the Rome Statute, the category of war crimes being the most elaborate. For an individual to be prosectuted and ultimately convicted for the crime of genocide, the decisive criterion is to be found in Article 2 of the Genocide Convention: the requirement of an intent to destroy has to be met.

The ICTY in the Krstić (pronunciation: kerr-steech, a name that oddly translates as Mr. Cross-stitch) case has set out that the term "in part", as meant in Article 3 of the Genocide Convention, contains a substantiality requirement. The Trial Chamber determined that Krstic had the intent to kill, thus, the requirements of Art. 4(2)(a) of the Rome Statute have been met (para 598 case IT-98-33-T, Prosecutor v. Krstić). Although the ICTY Appeals Chamber in the Judgment of 19 April 2004 acknowledges that the Trial Chamber should have exressed its reasoning more carefully (para 22), the remark is made that the Trials Chamber was correct when determining that the part of the group that has been killed, was "substantial" as with respect to the crime of genocide.
In concluding that some members of the VRS Main Staff had intented to destroy this substantial part of a group, the Trial Chamber did not depart from the legal requirements for genocide (para 38).

For an individual to be prosecuted for crimes against humanity, a "specific intent" exists when there is  "knowledge of the attack". This is a less strict criterion than is the "intent to destroy" requirement for prosecuting one for the crime of genocide.

How does one determine, however, when the individual has had the "intent to kill"? The mental element as such, mens rea, is described in Article 30(2) of the Rome Statute of the ICC: a person has intent where (a) in relation to conduct, that person means to engage in the conduct; (b) in relation to a consequence, that person means to cause that consequence or is aware that it will occur in the ordinary course of the events.

The grounds for excluding criminal responsibility are to be found in Articles 31 and 32 of the Rome Statute. Article 33 provides possible grounds for the exclusion of criminal responsibility; paragraph 1 gives a negative formula: "..shall not relieve that person of responsibility, unless..." one of the three options in (a)(b)(c) applies.

1.2.3. temporal jurisdiction
The first of the general principles of criminal law, as laid down in part 3 of the Rome Statute, define the temporal jurisdiction of the ICC:  from "nullum crime sin lege", "nulla poena sine lege" and the non-retroactivity ratione personae, follows that the Court has no jurisdiction with respect to criminal activities committed prior to the entry into force of the Rome Statute, see Art. 11 along with 24 of the Rome Statute.

1.2.4. territorial and personal jurisdiction
The Court can exercise its jurisdiction if a state within the territory of which the conduct has taken place, is a party to the Rome Statute or has accepted the ICC's jurisdiction in accordance with paragraph 3 (Art. 12 Rome Statute).  From this follows that the ICC can exercise jurisdiction if the state of which an accused individual is a national, is a party to the Rome Statute or has accepted its jurisdiction as set out.

Note that the limitation of territorial and personal jurisdiction does not apply to the situations as provided for in Articles 13(b) and 15 ter of the Rome Statute.

1.2.5. no universal jurisdiction
No universal jurisdiction of the ICC is recognized; with respect to its complementary role, Article 12(2) of the Rome Statute provides that State consent is a precondition to the exercise of jurisdiction by the ICC.

1.3. What are the conditions for action by the ICC?
There are three ways to enable the ICC's jurisdiction, Article 13 of the Rome Statute:

1. A State Party may refer a situation to the Prosecutor, in accordance with Article 14 of the Rome Statute (Art. 13(a) Rome);
2. The Security Council of the UN, acting under Chapter VII of the UN Charter, may refer a situation to the Prosecutor (Art. 13(b) Rome);
3. The Prosecutor may initiate investigations proprio motu (Article 13(c) in conjunction with Article 15 Rome).

Note that referral by a State Party and investigation proprio motu by the Prosecutor, Article 13(a) and (c) Rome, are subject to the conditions in Article 12(2)(a)(b) of the Rome Statute.

2. How do the jurisdiction of the ICC and the Tribunals differ in relation to domestic courts?
As said before, the nature of the jurisdiction of the ICC is complementary; the Court has no primacy, as states have first responsibility, unless they are unwilling or genuinely unable to carry out investigation or prosecution, which is an issue of admissibility. Once a case is genuinely being investigated or prosecuted by a domestic court, the case will no longer be admissible before the ICC: look up relevant Articles 1 and 17-19 of Part 2 of the Rome Statute.

No such conditions are imposed on the Criminal Tribunals; the International Criminal Tribunal of the former Yugoslavia shall have primacy over national courts, in accordance with Art. 9(2) of the ICTY. The same holds good for the Rwanda Criminal Tribunal, as Article 8(2) of the ICTR (UNICTR) was a mere predecessor of the concurrent jurisdiction provisions in the ICTY.

The International Tribunals have another main advantage over the ICC in common: the permanent status of the ICC demands from the Court that individuals only be prosecuted for or convicted of crimes that meet the condition of nullum crime sini lege in accordance with Article 22 of the Rome Statute. No such provisions are to be found in the ICTY and ICTR: the International Criminal Tribunals are able to respond to recent activities, regardless of a strict ex ante codification of crimes that the individual could be convicted of.

3. How is the responsibility of the individual addressed?
3.1. Individually or jointly committed crimes and contribution to the commission of crimes
An individual should be held criminally responsible and liable for punishment for a crime within the jurisdiction of the ICC, if that person:
1. Commits such a crime, whether as an individual, jointly with another or through another person
(art. 25(3)(a) Rome Statute);
2. For the purpose of facilitating the commission of such a crime, aids, abets or otherwise assists
(art. 25(3)(c) Rome Statute); 
3. In any other way contributes to the commission or attempted commission of such a crime. Such contribution shall be intentional and shall either be made with the aim of furthering the criminal activity or be made in the knowledge of the intention of the group to commit the crime
(art. 25(3)(d)(i)(ii) Rome Statute).

3.2. Responsibility of commanders
A person shall be held criminally responsible if that person:
1. Orders, solicits or induces the commission of such a crime (art. 25(3)(b) Rome Statute);
2. A commander shall be held responsible for crimes committed by forces under his effective command and control, where that military commander either knew or should have known that the forces were committing such crimes and that military commander failed to take necessary and reasonable measures within his power to prevent or repress their commission [..] (Art. 28 Rome Statute).

3.3. Persons pursuant to superior orders
The fact that a crime is committed by a person, pursuant to an order of a Government or a superior, shall not relieve that person of responsibility, unless that person was under a legal obligation to obey, the person did not know that the order was unlawful and the order was not manifestly unlawful (Article 33(1)(a)(b)(c) Rome Statute). However, the crime of genocide and crimes against humanity are manifestly unlawful; thus, a person cannot be relieved from responsibility with respect to such crimes (Art. 33(2) Rome Statute).

3.4. State responsibility
Article 25(4) provides that no provision in the Rome Statute relating to individual responsibility shall affect the responsibility of States under international law.

4. How can a state exercise domestic jurisdiction over international crimes?
The principles from which state jurisdiction is derived, are territoriality, protection, nationality and universality.

4.1. Territoriality principle
Regarding the territoriality principle, a distinction can be drawn between the subjective territoriality (initiation of a crime) and the objective territoriality/ effects doctrine (fulfilment of a criminal offence). If two states are concerned, both the state in which the crime was initiated and the state in which the crime was executed, are entitled to exercise their jurisdiction.

4.2. Nationality principle
The active nationality principle implies that a state may exercise its jurisdiction over its own nationals, regardless of the territory on which a crime was committed.
The passive nationality principle aims to protect a state's own nationals against offences, even if they are committed by another national in another state. Exercising passive nationality would interfere with the right of another state to exercise its territorial jurisdiction.

4.3. Protective principle
The protective principle implies that a state can exercise jurisdiction over non-nationals in the territory of another state. The requirement is that an offender commits a crime that affects the vital interests of a state.

4.4. Universality principle
Certain crimes are so grave in nature, that a universal protection against the commission of such crimes is required, regardless of territoriality and nationality issues. From this follows that states need to exercise universal jurisidiction with respect to the prosecution of offenders.

Note that treaty law imposes on states, party to a treaty, the obligation to exercise universal jurisdiction regarding the repression of universally recognized, grave crimes. The crimes of genocide and torture are crimes of such gravity. Article 6 of the Genocide Convention stipulates that an offender shall be tried by a competent tribunal, which may exercise its jurisdiction over the territory of the Party State in which the crime of genocide was committed. The preamble to the Torture Convention reads that "the desire is to make more effective the struggle against torture and other cruel treatment throughout the world".  Article 7 of the Torture Convention stipulates that the State Party submit the case to its competent authorities for the purpose of prosecution, assumed that the requirements from Art. 4-6 have been met (territory issues).

5. The jurisdiction of the ICTY and ICTR
While the ICC and Neuremberg Tribunal were established by a treaty, the ICTY and ICTR were established by binding Resolutions of the UN Security Council, acting under the provisions of Chapter VII of the UN Charter. Recall that Articles 7 and 8 of the ICTY and ICTR Statutes provide the Tribunals with both territorial and temporal jurisdiction.

5.1. The Appeals Chamber in the Tadić case of 2 October 1995: Kompetenz-Kompetenz
Concerning its jurisdiction, the Appeals Chamber in the Tadić Interlocutory Appeal of 2 October 1995 remarks that, according to the principle of "Kompetenz-Kompetenz" or "la compétence de compétence", the Tribunal has the incidental or inherent competence jurisdiction to determine its own jurisdiction (para 18). It is a necessary component of in the exercise of the judicial function of the tribunals and as such, this practice was accepted by general international law.

With respect to the questioning of the power of the UNSC to set up ICTY by means of a resolution, the Appeals Chamber determines that the legal basis is to be found in the authority of the Security Council, as was decided by the (paras 32-38 and 40).

5.2. Questioning the primacy of International Tribunals
Although the Tribunals have concurrent jurisdiction with domestic courts, the Tribunals have primacy with respect to the prosecution of international crimes, as laid down in Articles 8 of the ICTR Statute and 9 of the ICTY Statute.

The second ground of appeal in the 1995 Tadić Decision on the Defence Motion by the  ICTY Appeals Chamber attacks the primacy of the International Tribunal over domestic courts (para 49).
However, the plea of State sovereignty must be dismissed. The Appeals Chamber provides us with several important considerations.
                  The public revulsion against similar offences [crimes against humanity] brought about the establishment of an international judicial body by an organ of an organization representing the community of nations: the Security Council. This organ is empowered and mandated, by definition, to deal with trans-boundary matters which may affect "international peace and security". It would be a travesty of law, should the concept of State sovereignty be allowed to be raised succesfully against human rights. When an international tribunal such as the present one is created, it must be endowed with primacy over national courts. Otherwise, there would be a danger of international crimes being characterised as "ordinary crimes" (para 58).

6. Do HRSO enjoy immunity before the ICC and Tribunals?
One final remark on the immunity of HRSO from foreign jurisdiction. It should be clear that an incumbent HRSO or a former HRSO with respect to crimes committed in acting out official capacities, cannot enjoy immunity before the ICC and the International Tribunals. Article 27 of the Rome Statute stresses that HRSO do not enjoy immunity before the ICC; Articles 7(2) of the ICTY and 6(2) of the ICTR read that the "official position of any accused person, whether as Head of State of Government, shall not relieve such person of criminal responsibility nor mitigate punishment".

Ius ad bellum & ius in bello: international humanitarian law

1. Ius ad bellum & ius in bello: Hague law and Geneva law
There is a distinction between ius ad bellum and ius in bello, the first regarding the waging of war, the latter regarding warfare. Armed conflict is governed by the Hague law on one hand, aiming to curb the conduct of hostilities, and Geneva law, aiming to protect the victims of an armed conflict.
Both the Hague law and Geneva law are recognized as a fundamental part of customary international law, as the Court states in para 79, 80 of the Nuclear Weapons Advisory Opinion (a reference to the 1949 Corfu Channel case is made):

"It is undoubtedly [..] rules of humanitarian law applicable in armed conflict are so fundamental to the respect of [..] "elementary considerations of humanity", that the Hague and Geneva Conventions are to be observed by all States, whether or not they have ratified the conventions that contain them, because they constitute intransgressible principles of international customary law" (para 79). Furhermore, the Court notes that these principles of humanitarian law are part of ius cogens (para 83).

From this follows that, regardless of the act of ratification by States, the rules codified in the Hague and Gevena Conventions apply to armed conflict, because these conventions embody the rules of customary international law.

1.2. The Hague law
Since the 1868 St. Petersburg Declaration, the Hague law has incorporated conventions to outlaw certain types of weaponry, as the 1993 Chemical Weapons Convention is one of these coventions being considered part of the Hague law.

1.3. Geneva Conventions and their Additional Protocols
The four Geneva Conventions are, in a particular order, as follows:
Convention I:    protection of wounded and sick members of armed forces;
Convention II:   protection of wounded, sick and shipwrecked members of armed forces at sea;
Convention III:  treatment of prisoners of war;
Convention IV:  protection of civilians

The three additional protocols are:
AP I:                detailed rules of protection of victims in international armed conflicts (IAC);
AP II:               regulation of non-international armed conflicts (NIAC);
AP III:              rules on additional distinctive emblem of the red crystal

2. The scope of humanitarian law: defining an armed conflict
There has always been uncertainty on the precise scope of humanitarian international law. Common Article 2 of the Geneva Convention provides that the Convention "shall apply to all cases of declared war or any other armed conflict which may arise between two or more of the High Contracting Parties, even if the state of war is not recognized by one of them".

Hence, the concept of an "armed conflict" has to be defined. The ICTY Appeals Chamber does so in the 1995 Decision on the Defence Motion for Interlocutory Appeal on Jurisdiction in the Tadić case (2 October 1995): "..we find that an armed conflict exists whenever there is a resort to armed forces between States or protracted armed violence between governmental authorities and organized armed groups or between such groups within a State. Humanitarian law extends beyond the cessation of hostilities" (para 70).

As you might have noticed, the threshold for a NIAC is higher than is the case with an IAC. Humanitarian international law applies at the very moment of any act of force between States- with respect to international humanitarian law, one could say it is "war at first shot", as Common Article 2 of the Geneva Convention implicitly makes clear. NIACs, on the other side, require "protracted or large-scale armed violence" for international humanitarian law to be applicable.

2.1. Lotus doctrine and si omnes clause
The rationale behind this distinction is State sovereignty. International law would foremost be applied in conflicts between States, or High Contracting Parties to the Conventions. A si omnes clause has a very limited scope, stipulating that provions could only apply if States, party to a conflict, were both parties to the convention that would be applied. According the Lotus doctrine, only the specific prohibition of methods of warfare would govern interstate conflicts; otherwise, much was permissible.

2.2. Martens' clause
Фёдор Фёдорович Мартенс, Fjodor Martens, designed the general savings clause. This clause is included in Article 1(2) of AP I; furthermore, Common art. 2 of the Geneva Convention expressly rejects the si omnes clause. It does so by stating "Although one of the Powers [to a conflict] may not be a party to the present Convention.."
Note that paras 1-3 from Art. 60 of the VCLT do not apply to provisions relating to humanitarian treaties, Art. 60(5) VCLT. This provision stresses the importance of international humanitarian law: treaties concerning humanitarian law should not be terminated along the line of material breach by another party.

3. Principles of humanitarian law
Four principles underlie the rules of international humanitarian law as expressed in the conventions and additional protocols:
I.    Principle of distinction;
II.   Principle not to cause unnecessary suffering/ humanity principle;
III.  Principle of military necessity and proportionality;
IV.  Principle of precaution.

3.1. Principle of distinction
A distinction must be drawn between combatants ( defined by art. 43 of AP I) and civilians (defined by Art. 50 AP I).  A civilian is any person who does not belong to one of the categories referred to in Art. 4 (A)(1)(2)(3) and (6) of Convention III and art. 43 of AP I. Unless they take direct part in hostilities, civilians shall enjoy protection (Art. 51 (3) AP I). As Articles 48 (basic rule), 51(2) and 52(2) express, civilians cannot lawfully be made objects of attack. Note that enemies hors de combat will be safeguarded by Art. 41 of AP I; Article 41(2) AP I defines persons hors de combat which cannot be made objects of attack.

A combatant cannot be deprived of his right to be combatant, whether he has violated rules of international law or not, Art. 44(2) AP I. Members of the armed forces of a Party to a conflict, have the right to participate directly in hostilities, Art. 43(2) AP I. Any combatant as defined in Art. 43, who falls into the power of an adverse Party, shall enjoy the prisoner-of-war-status, Art 44(1) AP I. If a combatant fails to distinguish himself from civilians, Art. 44(3) AP I, he will not enjoy the prisoner-of-war-status, Art. 44(4) AP I; however, he will be given the equivalent of the protection accorded by Convention III and AP I. In order to garantuee as much protection as possible to all categories of combatants and non-combatants, main rule prescribes that anyone who cannot be considered a combantant in line with Art. 43 AP I, will be considered a civilian, Art. 50 AP I.

Civilians that take part in hostilities, become objects of attack (Art. 51(3) AP I), but they will not enjoy the status of prisoner-of-war when captured; if article 4 of Geneva Convention III does not apply, Article 45(3) in conjunction with Article 75 AP I affords the person, who is not entitled to prisoner-of-war-statues, the right to protection. Otherwise, Geneva Convention IV may apply.
There is a difference between civilians taking part in organized hostilities and civilians participating in levée en masse. The latter, spontaneously participating in non-organized hostilities, do become prisoners-of-war in the event of being captured, Article 4A (6) of Geneva Convention III.

Indiscriminate attacks are prohibited, Art. 51(4) and (5) AP I. Some conventions are designed to expressly prohibit the use of certain weaponry, such as the 2010 Convention on Cluster Munitions.

The Threat and use of nuclear weapons Advisory Opinion of 8 July 1996 discusses both the principles of distinction and the principle not to cause unnecessary suffering in paras 95-97. The Court's summary of the principles that constitute "the fabric of humanitarian law" is to be found in para 78.

3.2. Principle not to cause unnecessary suffering (humanity)
Necessity cannot be invoked to justify military actions at any cost, as Martens' clause aims to codify. The basic rules in Art. 35 of AP I stress this principle not to cause unnecessary suffering as a result of warfare. From the application of Common Article 3 follows that the humanity principle applies to NIACs as well.

Regarding Common Article 3, the ICJ notes in the Nicaragua case that:

"The importance of the principles that the Geneva Conventions and other relevant instruments purport to codify is [..] demonstrated by Articles 63, 62, 142 and 158 of Geneva Conventions I, II, III and IV respectively. These provisions allow for state parties to denounce the conventions unilaterally. However, the denunciation: "Shall in no way impair the obligations which the parties to the conflict shall remain bound to fulfil by virtue of the principle of the law of nations, as they result from the usages among civilized peoples, from the laws of humanity and the dictates of public conscience" (para 218).

3.3. Principle of military necessity and proportionality
As the Court states in the Threat or use of nuclear weapons Advisory Opinion, it is prohibited to use weapons causing the combatants unnecessesary harm, that is to say, a harm greater than unavoidable to achieve legitimate military objectives (para 78).

The last sentence of Art. 51(5)(b) AP I classifies "attacks that are excessive in relation to the military advantage anticipated" as indiscriminate and therefore prohibited.

To NIACs, customary international law imposes on parties to the conflict an equal obligation to refrain from causing greater harm than unavoidable to achieve military objectives.

3.4. Principle of precaution
The principles of humanity and military necessity imply the principle to take precautionary measures. In the conduct of military operations, Art. 57 AP I stipulates that constant care shall be taken to spare civilians and civilian objects. While AP I does not apply to NIACs, customary international law imposes on the parties to a NIAC the obligation to take precautions in order to prevent unnessary suffering.

4. NIACs
4.1. Defining NIACs and the application of Common Art. 3
On deciding whether the armed conflict in the Tadić case could be considered an international armed conflict, the Appeals Chamber in the Judgment of 15 July 1999 stated that "in order to attribute the acts of military or paramilitary groups to a State, it must be proved that the State wields overall control [..]" (para 131).

Although its scope is limited, Geneva Convention Common Art. 3 applies to NIACs. In the Decision on the Defence Motion for Interlocutory Appeal on Jurisdiction of 2 October 1995 in the Tadić case, the ICTY Appeals Chamber makes clear that a higher threshold has to be passed for an internal conflict to qualify as a NIAC (para 70).

In the Tadić trial of 7 May 1999, the ICTY Trial Chamber has set out which requirements have to be met in order to pass the threshold for the application of rules regarding a NIAC: "The test applied to the existence of an armed conflict for the purpose of the rules contained in Common Article 3 focuses on two aspects of a conflict: the intensity of the conflict and the organization of the parties to the conflict" (para 562).

4.2. NIACs and AP II
Many of the provisions of AP II represent customary international law. The threshold in Additional Protocol II (which governs NIACs) can be derived from Article 1(1) AP II:

"..organized armed groups which, under responsible command, exercise such control over a part of its territory as to enable them to carry out sustained and concerted military operations".

The scope of AP II is, thus, limited, as Article 1(2) AP II puts it: "This Protocol shall not apply to situations of internal disturbances and tensions such as riots, isolated and sporadic acts of violence."

Like I noted before, the explanation for the restricted reading of the regulation of NIACs is State sovereignty. Also, States might not want to qualify internal conflicts with armed (rebel) groups as NIACs, for qualifying a conflict as such, implicitly means recognizing and eventually legitimizing the existence and actions of those groups.

5. The value of humanitarian law
What is exactly the value of international humanitarian law? Although the (codification of) customary international law aims to guarantee human rights and stems from universal human ideals of what global society should be like, it goes to show that many (non-) state actors don't live up to guarantee those rights. When non-State actors and States lack natural authority, one could image well how these actors resort to the threat with or use of violence and how they would rely on an arms race to scare off future, existent or imaginary enemies; living up to their human rights commitments would be the last to be concerned about. In practice, non-compliance is the rule rather than the exception. Even if all parties to a (human rights) treaty give their consent to be bound, there will always be ambiguity when conflicts arise. That is why many of the rules of international law apply in theory, but not in practice.

Recommended reading:
Typology of armed conflicts in international humanitarian law, S. Vité, March 2009;
International Humanitarian Law, H.P. Gasser, March 2011, available at Oxford PIL.

Immunity from foreign jurisdiction for States and HRSO

1.1. State immunity: par in parem non habet imperium
Codified in the UN Convention on Jurisdictional Immunities of States and Their Property (abbreviated UNCSI), the rules on State immunity are of customary international law. Though in issues governed by certain treaties like the 1972 European Convention, general customary law does not apply. General customary law shall only be excluded when immunity issues between member States of the European Convention arise.

As Article 5 of UNCSI reads:
"A State enjoys immunity, in respect of itself and its property, from the jurisdiction of the courts of another State subject to the provisions of the present Convention".
Subsequently, Art. 6 obliges States to refrain from exercising jurisdiction before its court against another State.

The underlying principle is that all States are sovereign and equal (as Article 2(1) of the UN Charter puts it). Thus, the UNCSI solely applies to immunity from foreign jurisdiction: a State could and should not be prosecuted before a domestic foreign court.  Note that State immunity is derived from State sovereignty, which relates to the rule that incumbent high-ranking State officials are also immune from the jurisdiction of foreign States. States have legal personality, therefore they enjoy immunity ratione personae: immunity from jurisdiction and enforcement.

1.2. Subjects of State immunity
For the purposes of the Convention on Jurisdictional State Immunities, a "State" means, Art. 2(1):
i. the State and its various organs of government;
ii. units of a federal State or political subdivisions which are entitled to perform acts in the exercise of sovereign authority and are acting in that capacity;
iii. agencies "  ";
iv representatives of the State, acting in that capacity.

From this follows that incumbent HRSO enjoy full immunity from foreign jurisdiction, a result of the classic view on sovereign immunity, as discussed under para 1.1.

1.3. Relative immunity
A distinction is drawn between acta iure imperii (governmental acts) and acta iure gestionis. States could not enjoy absolute immunity for their acta iure gestionis, see Art. 10(1) of UNCSI:
"If a State engages in a commercial transaction with a foreign natural or juridical person [..] the State cannot invoke immunity from that jurisdiction in a proceeding arising out of that commercial transaction". Paragraph 1 does not apply in case of one of the exceptions, mentioned in the second paragraph of Art. 10.

How does one determine, whether a contract or transaction is an acta iure gestionis? According to Article 2 of the UNCSI, reference should be made primarily to the nature of the contract or transaction; however, its purpose should also be taken into account. The focus shifts from the initial purpose of a transaction, to the nature of a transaction, to prevent States from using the "veil" of acta iure imperii in order to escape their obligations by invoking full immunity from foreign jurisdiction.

Other proceedings in which a State cannot invoke immunity, concern: contracts of employment
(Art. 11), personal injuries and damage to property (Art. 12), ownership (Art. 13), intellectual property (Art. 14)  and so on, see Part III of UNCSI.

1.4. Waiver of immunity
No problems will arise when a State has expressly consented to the exercise of jurisdiction by a foreign court, in the cases, mentioned in Article 7 of UNCSI. A State could be considered to have consented to the exercise of a foreign court implicitly, as Article 8(1) makes clear, unless paras 2-4 of Art. 8 UNCSI apply.

1.5. Jurisdictional Immunities of the State, ICJ 3 February 2012
Ferrini case: Germany v. Italy, Greece intervening
To an important extent, State immunity is based on the rules of customary international law, as the ICJ sets out in paras 53-58 of the 2012 Immunities case.

State immunity does not imply that a State cannot be held responsible for its actions; as was discussed before, State immunity solely implies that a State could not be prosecuted before a domestic foreign court. See para 53:  "The Court is not called upon to decide whether these acts were illegal; the question for the Court is whether or not, in proceedings regarding claims for compensation arising out of those acts, the Italian (domestic) courts were obliged to accord Germany immunity". A State prosecuting another State, could in its turn be held responsible for violating the right to invoke immunity from foreign jurisdiction.

1.5.1. Do the breach of ius cogens and territorial torts allow for denial of immunity?
Does customary international law prevent a State from lawfully invoking immunity in respect of the "Territorial Tort Principle", even is an act on the territory of a forum State was performed iure imperii? The Court considers it is not called upon in the present proceedings to resolve the question, whether there is in customary law a "tort exception" to State immunity to acta iure imperii in general (para 65).
        The Court agrees that the result of Art. 31 of the European Convention as a clause, is that the immunity of a State for the acts of its armed forces, falls out of the Convention and has to be determined by reference to customary law.The consequence is, however, that the inclusion of the "Territorial Tort Principle" cannot be treated as support for the argument that a State is not entitled to immunity for torts, commited by its armed forces (para 68).
       Moreover, State practice in the form of judicial decisions, supports the proposition that State immunity for acta iure imperii continues to extend to civil proceedings for acts occasioning [..] by the armed forces, even if the acts take place on the territory of the forum State. That practice is accompanied by opinio iuris, as a number of national courts made clear that customary law required immunity. The almost complete absence of contrary jurisprudence is significant (para 77).
       The Court concludes that, under customary law, a State is not deprived of immunity by reason of the fact that it is accused of serious violations of international human rights law. The question of whether immunity might apply in criminal proceedings is, however, not an issue in the present case (para 91).
       As to the relationship between ius cogens and State immunity, the Court considers that there exists no conflict between the two legal concepts, as the two sets of rules address different matters. The rules of State immunity are procedural in character and are confined to determining whether or not the courts of one State may exercise jurisdiction in respect of another. They do not bear upon the question whether or not the conduct in respect of which the proceedings are brought, was lawful or unlawful. Recognizing State immunity does not amount to recognizing as lawful the breach of ius cogens and so cannot contravene the principle in Article 41 of the ILC on State Responsibility
(para 93).

2. Immunity from jurisdiction for High-Ranking State Officials (HRSO)
As was set out above, the immunities in respect of HRSO are derived from the principle of sovereign immunity; the immunities of a HRSO are interrelated with State immunity. As a matter of fact, only a State can waive the immunity of an HRSO. An incumbent HRSO enjoys both immunity ratione materiae and ratione personae. Note that, after a HRSO ceases to hold the office, he or she will no longer hold all of the immunities. A State may try a former HRSO in respect of acts committed in a private capacity (Arrest Warrant 2002, DRC Congo v. Belgium, para 61).

2.1. Relevant considerations in the Arrest Warrant Judgment of 11 April 2002
Yerodia Ndombasi case, Congo v. Belgium
2.1.1. HRSO and full immunities, regardless of a official or private capacity
Certain holders of high-ranking office in a State enjoy immunities from jurisdiction in other States, both civil and criminal. It is only the immunity from criminal jurisdiction and the inviolability of an incumbent Minister for Foreign Affairs, that fall for the Court to consider (para 51).
              The rationale behind the immunity for HRSO is as follows. In customary international law, the immunities accorded to [..] are not granted for their personal benefit, but to ensure the effective performance of their functions on behalf of their respective States (para 53).
              When abroad, a HRSO (as is a Minister for Foreign Affairs i.c.) enjoys full immunity from criminal jurisdiction throughout the duration of his office [...] to protect the individual against any act of authority by another State which would hinder him in the performance of his duties (para 54).
In this respect, no distinction can be drawn between acts performed by a HRSO in an "official" capacity, and those claimed to have been performed in a "private" capacity (para 55).

2.1.2. Considerations regarding Opinion ex parte Pinochet
According to Belgium, the Pinochet decision recognizes an exception to the immunity rule when Lord Millett stated that "international law cannot be supposed to have established a crime [..] or when Lord Phillips said that "no established rule of international law requires state immunity ratione materiae to be accorded in respect of prosecution for an international crime" (para 56).
           The Congo cites Lord Browne-Wilkinson's statement that "this immunity, enjoyed by a head of  state in power is a complete immunity, attached to the person of the head of state and rendering him immune from all actions or prosecutions"  (para 57).
           The Court has been unable to deduce from [..] practice that there exists under customary law, any form of exception to the rule according immunity from criminal jurisdiction and inviolability to incumbent Ministers, where they are suspected of having commited war crimes. The rules concerning criminal responsibility of HRSO likewise do not enable to conclude that any such exception exists in customary law in regard to domestic courts (para 58).

2.1.3. Is impunity a result of immunity?
It should be noted that the rules governing the jurisdiction of foreign courts must be distinguished from those, governing jurisdictional immunities; jurisdiction does not imply absence of immunity and absence of immunity does not imply jurisdiction. The obligations of prosecution and extradition of serious crimes that are imposed on States, do in no way affect immunities under customary law, including those of HRSO (para 59).
         The immunity from jurisdiction enjoyed by HRSO does not mean that they enjoy impunity in respect of crimes committed, as immunity from criminal jurisdiction and individual criminal responsibility are quite separate concepts, the first being of a procedural nature, the latter being a question of substantive law (para 60).
         Acccordingly, the immunities enjoyed by an incumbent or former HRSO do not represent a bar to criminal prosecution in certain circumstances. The Court nouns four examples, the first being that jurisdictional immunity does not apply to trial in the domestic court of the HRSO; subsequently, the waiver of immunity by the represented State will cease the immunity from foreign jurisdiction; as mentioned, after a HRSO ceases to hold the office, he will no longer enjoy immunity for his acts commited in private (para 61).

2.1.4. Jurisdiction of International Criminal Tribunals
One important remark is that International Criminal Tribunals can try HRSO in criminal proceedings, as the Rome Statute in Article 27(2) provides that immunities of an incumbent or former HRSO shall not bar the Court from exercising its jurisdiction over such a person.

3. X v. Bow Street Metropolitan Stipendary Magistrate, Ex parte Pinochet Ugarte (No 3)
3.1.1. Defining the scope
The ICJ reasoned in its Jurisdictional Immunities case (Ferrini) of 2012, that a clear distinction should be made between State immunity and the criminal jurisdiction of a former HRSO: "Pinochet concerned the immunity of a former Head of State from criminal jurisdiction of another State, not the immunity of the State itself in proceedings to establish its liability to damages"(para 87 Fellini case).

3.1.2 Could torture, committed by a former HRSO, be considered an official act?
Immunity ratione personae attaches to the office, meaning that a former HRSO cannot invoke immunity with respect to acts committed in private during his time in office, while immunity ratione materiae can be invoked for the official acts that have been committed during his time in office.
        Regarding the Pinochet case, it is important to note that "The Republic of Chile accepted that the international law prohibiting torture, has the character of ius cogens or a peremptory norm". Chile is a party to the Torture Convention (Convention Against Torture, CAT).
       The question which has to be answered, is whether the alleged organisation of state torture by Senator Pinochet (if proved) would constitute an official act, committed as a Head of State. It is not enough to say that it cannot be part of his functions to commit a crime. Actions which are criminal under local law, can still have been done officially and therefore give rise to immunity ratione materiae. Can it be said that the commission of a crime which is an international crime against humanity and ius cogens, is an act done in an official capacity on behalf of the state?
       Under the CAT the international crime of torture can only be committed by an official [...] If immunity applies, there can be no case outside of Chile in which a succesful prosecution can be brought (unless the State is prepared to waive its right to its officials' immunity). One of the main objectives of the CAT: universal jurisdiction over torture, committed by HRSO, would be frustrated by upholding immunity for former HRSO.  The notion of continued immunity for former HRSO is inconsistent with the provisions of CAT.