3 Filling the gap? Terrorism and other international legal norms

42



‘terrorism’ in international law



domestic law. In addition, as discussed in more detail in Chapter 4, acts

commonly referred to as ‘terrorist’ may amount to other crimes under

international criminal law, including customary law of general application. Notably they may amount to war crimes (if carried out in armed

conflict) and crimes against humanity (whether or not there is an armed

conflict), provided the necessary elements of those crimes are met, including that they be committed against the ‘civilian population’.102

The crimes mentioned above do not provide comprehensive coverage of the range of possible terrorist acts: for example, attacks aimed at

terrorising the civilian population in time of peace, which do not meet

the widespread or systematic threshold requirement of crimes against

humanity, and in a state that has not ratified the specific conventions,

would probably not be proscribed under international law.103 But even

in such circumstances, acts of international terrorism will be covered by

ordinary domestic law. Whether or not domestic law criminalises terrorism as such, it will inevitably prohibit murder or attacks on the physical

integrity of persons or on property.

The second point to note is that the lack of a definition of terrorism

does not signify a lack of obligations on states to refrain from participating

in or supporting acts of terrorism and to take certain proactive counterterrorist measures. Under the general rules governing relations between

states, a state is obliged for example ‘to not knowingly allow its territory to

be used in a manner contrary to the rights of other states’,104 and to refrain

from the threat or use of force, direct or indirect, against another state.105

As regards the treatment of persons subject to a state’s ‘jurisdiction’ or

‘control’, the state is also obliged under international human rights law

not only to refrain from acts that jeopardise human security, but also to

prevent and punish them.106 States also have specific obligations in respect

102



103



104

105

106



Terrorism against combatants would not be covered by either definition which requires

that the civilian population be the object of the terror or the prohibited acts amounting

to crime against humanity. See, e.g., ICC Statute definitions.

Some have suggested that what is needed by way of a comprehensive definition is this

definition of war crimes of terror, but applicable in time of peace, although this is, like other

proposals, controversial. See website of the Terrorism Prevention Branch of the Office for

Drug Control and Crime Prevention (http://undcp.org/terrorism definitions.html) and

concern expressed in Guzman, Terrorism and Human Rights No. 1, p. 191.

Corfu Channel (United Kingdom v. Albania), Merits, ICJ Reports 1949, p. 22.

See state responsibility in international law and obligations to refrain from force, discussed

at Chapters 3 and 5.

This is subject to the acts falling within the purview of human rights obligations: acts in

other states generally do not, unless as a result of the exercise of the state’s authority

and control abroad (see controversy surrounding extra-territoriality, at Chapter 7,



terrorism and other international legal norms



43



of the repression of ‘terrorism’ as such.107 These include, for state parties

to them, the obligations arising out of the specific terrorism conventions

discussed above. But obligations may also arise from, or be reflected in,

UN resolutions, such as the far reaching Security Council resolutions post

September 11.108

The importance of the existing, and proposed, terrorism conventions

lies in the provision of a framework for the obligations regarding international cooperation,109 ensuring, for example, that states are obliged

to ‘extradite or prosecute’ persons suspected of the offences covered

by them.110 While the obligation to investigate and prosecute is not

new or limited to these conventions,111 they seek to facilitate the effective discharge of the cooperation obligation and to remove obstacles to

extradition.112 Particular ‘modalities’ of cooperation aimed at discharging the general obligation to cooperate, such as intelligence and evidence

sharing, transfer of criminal proceedings, freezing and seizure of assets,



107

108



109

110



111



112



para. 7A.2.1. As noted above, terror within a state is not generally thought to be covered by the concept of ‘international terrorism’ for the purpose of the specific terrorism

conventions, or the Draft Comprehensive Convention.

As discussed below, the force of those obligations may be weakened or undermined by

divergent interpretations of what is covered, and excluded, by the term.

SC Res. 1368, above, note 61, stresses that ‘those responsible for aiding, supporting or

harbouring the perpetrators, organisers and sponsors of these acts will be held accountable’. Unlike SC Res. 1373 (2001), (above, note 1), this is not a binding Chapter VIII

resolution, however. SC Res. 1373, at paras. 1 and 2, obliges states to adopt wide ranging measures including criminalisation, freezing of assets and denial of safe haven, as

discussed at Chapter 3.1.2.

Cooperation is discussed in more detail in Chapter 4, para. 4A.2 and the human rights

issues raised are highlighted in Chapter 7, para. 7A.4.3.8.

On the obligation to extradite or prosecute (aut dedere aut judicare) see also Chapter 4.

The obligation as enshrined in, for example, the specific terrorism conventions is not

absolute, and has been criticised for the lack of clarity as to whether a state is only obliged

to extradite if it has first declined to submit the case for prosecution domestically. See

‘International Terrorism: Challenges and Responses’, Report from the International Bar

Association’s Task Force on International Terrorism, 2003, Chapter 7 (on file with author).

The conventions are not unique in this sense and the duty to extradite or submit for

prosecution crimes under international law, including war crimes and crimes against

humanity, which would include serious cases of terrorism, and to cooperate with other

states in respect of the same, is well established.

The usual requirements of extradition law (such as in some cases the ‘double criminality’

requirement that offences must be prohibited in the requested state as well as in the

state requesting extradition, or the ‘political offences’ exception), do not operate as a

bar to extradition. Developments seeking to further remove obstacles to extradition, or

to streamline the extradition process, have been initiated, or advanced with renewed

impetus, post September 11, some with potentially troubling human rights implications.

See Chapter 4, para. 4B.2.2 and para. 7A.8.



44



‘terrorism’ in international law



execution and recognition of foreign judgments, or indeed extradition

provisions, such as ‘conditional extradition,’113 have been addressed selectively in particular treaties.114 It has been suggested that if there is a gap

that the potential Draft Comprehensive Convention might fill, it may

not relate so much to the definition, but to the lack of a comprehensive

framework for international cooperation, covering all such modalities,

including clarifying the hitherto irregular, and at times confusing, rules

regarding extradition.115

In conclusion, the focus on and overuse of the terrorism terminology

may obscure the extent to which resort to terrorist tactics is already regulated by other areas of international law. As is often the case, the problem

lies more with the poor enforcement of existing norms, including but

going beyond specific terrorism norms, than with the lack of a generic

definition. In this respect it is noted that the Security Council’s call to

states to ratify existing terrorism conventions appears to have borne some

fruit although the crucial challenge in that respect remains implementation.116 While a generic definition in a global convention, if it could be

achieved and could garner near universal support, may serve the interests of legal certainty and the efficiency of inter-state cooperation, what

is clear is that its absence does not mean a legal void or necessitate legal

paralysis.



2.4 Conclusion

Given the outstanding differences of view on its key elements, it is difficult

to sustain that international terrorism is, per se, a discrete and identifiable

international legal norm. But, as discussed, the absence of a generic definition of terrorism leaves no gaping hole in the international legal order.

Rather it would appear to be the case that what we commonly refer to

as terrorism, although perhaps not defined as such, would most likely be

prohibited by other international legal norms irrespective of the existence

or absence of a generic definition of terrorism. In one view then, the lack

of a definition of terrorism is just not that significant. As one commentator noted: ‘Terrorism is a term without legal significance. It is merely a

convenient way of alluding to activities, whether of states or individuals,

113

114

116



Article 8(2), International Convention for the Suppression of Terrorist Bombings 1998.

115

See IBA Task Force, ‘International Terrorism’, ch. 7.

Ibid.

Many of the existing specific conventions are already widely ratified, though not necessarily implemented. See Chapter 4, section B.



conclusion



45



widely disapproved of and in which the methods used are either unlawful,

or the targets protected or both.’117

On the other hand, there can be little doubting the political currency of

the language of terrorism, particularly in the post September 11 world.118

The stakes were raised considerably by Security Council Resolution 1373,

which, in what has been described as a new ‘legislative’ role for the Security Council,119 imposes binding obligations on states to take extensive

counter-terrorist measures. These include criminalising ‘terrorism’ and

support for it, imposing serious penalties, freezing assets and excluding ‘terrorists’ from asylum and refugee protection. Notably, however,

1373 establishes these broad-reaching obligations in respect of terrorism

in general without providing a clear definition of the conduct towards

which such measures should be directed, and, by contrast to earlier binding decisions taken by the Council, without limitation as to the situation

or broad time frame in which it should apply.120

Imposing far-reaching obligations on the basis of an ambiguous

concept may reap unfortunate consequences. First, it may generate uncertainty as to the precise nature of states’ obligations towards the Council, and undermine those obligations. As was recently noted: ‘without

reaching an acceptable international definition of the term “terrorism”

one can sign any declaration or agreement against terrorism without

having to fulfil one’s obligations as per the agreement. For every country participatory to the agreement will define the phenomenon of terrorism differently from every other country.’121 Second, as discussed in

Chapter 7, it raises fundamental concerns regarding the human rights

implications of Resolution 1373, described by senior French law

117

118



119

120



121



Higgins, ‘General International Law’.

See for example the State of the Union Speech by the United States’ President, 20 September 2001: ‘Either you are with us, or you are with the terrorists. From this day forward,

any nation that continues to harbor or support terrorism will be regarded by the United

States as a hostile Regime’, available at http://www.whitehouse.gov/news/releases/2001/

09/20010920-8.html.

Orentlicher: see generally P. Szasz, ‘Note and Comment: The Security Council starts

Legislating’, 96 AJIL 901, October 2002.

While the September 11 attacks to which the resolution was responding would fall within

any definition of terrorism, and of other crimes under international law, Resolution 1373

is not in any way limited to that situation.

B. Ganor, ‘Security Council Resolution 1269: What it Leaves Out’, 25 October 1999, available at http://www.ict.org.il/articles/articledet.cfm?articleid=93. This reflection, made in

relation to SC Res. 1269 (1999) (above, note 13), is equally applicable to subsequent Security Council resolutions addressing terrorism, particularly SC Res. 1373 (2001), above,

note 1.



46



‘terrorism’ in international law



enforcement officials as having ‘opened the universal hunting season on

terrorism without defining it’.122

In conclusion, controversy surrounds the concept of terrorism in international law. Absent a clear and accessible meaning to be attributed to

the term, and consensus around the same, its susceptibility to abuse renders it an unhelpful basis for a legal, rather than political, analysis of the

September 11 events and the responses thereto. Subsequent chapters will

therefore address those events and responses based on other norms of

international law.

122



Statement of Mr Jean-Francois Gayraud, Chief Commissioner of the French National

¸

Police, and of the French judge David S´ nat, reported in Guzman, Terrorism and Human

e

Rights No. 2, p. 26.



3

International responsibility and terrorism



The question of responsibility for the events of September 11 permeates the discussion of lawful responses to those events, and as to against

whom any such response should be directed. Was a state responsible for

the September 11 attacks? Can al-Qaeda, bin Laden or other individuals be considered responsible under international law? To what extent

do the permissible responses to 9/11 depend on the answers to these

questions?

As will be apparent from the chapters that follow, state responsibility is

more relevant to some aspects of the framework of responses discussed in

this book than to others. State responsibility is not generally relevant to

the application of the criminal law framework, discussed in the following

chapter, although as discussed there it may be relevant to whether specific

crimes (notably war crimes and aggression) were committed in the course

of the September 11 attacks. By contrast, as discussed in Chapter 5, it is

a controversial question whether state responsibility for an armed attack

is a prerequisite to justify the use of force in self defence, or at least to

justify attacking that state itself.1 Questions of ‘state responsibility’ are

relevant, moreover, not only to the unfolding responses to 9/11 but, in

turn, to the obligations of other states to react to those responses. In certain

circumstances, the unlawful use of force, egregious violations of human

rights and international humanitarian law (discussed at Chapters 5, 6

and 7 respectively), may trigger the right, or in exceptional circumstances

the responsibility, of other states to take measures to end the wrong in

question.

The first part of this chapter assesses the responsibility of states in the

light of the rules on international responsibility. It considers the basis on

1



First, as discussed at Chapter 5, on one view, self defence under Article 51 of the UN Charter

only arises in response to attacks by states, although this view is increasingly controversial.

Second, measures involving the use of force in self defence must be ‘necessary’ to avert an

attack, suggesting that for such measures to be directed against the organs of a state, that

state must exercise a degree of control over the attack in question.



47



48



international responsibility and terrorism



which acts such as those that took place on September 11, perpetrated

by private individuals or organisations, may be attributed to a state such

that the state incurs legal responsibility for those acts. The second part

considers the consequences, under international law, of such state responsibility and refers to the circumstances in which other states may, or must,

react. The final section considers the extent to which so-called ‘non-state

actors’ – private individuals, organisations or entities, such as bin Laden

and al-Qaeda – may themselves incur ‘responsibility’ under international

law.



3.1 State responsibility in international law

3.1.1 Responsibility of a state for acts of terrorism

The international responsibility of a state arises from the commission of an

internationally wrongful act, consisting of conduct that (a) is attributable

to a state under international law and (b) constitutes a breach of an international obligation of the state.2 As regards acts commonly referred to

as ‘terrorist’, committed by individuals or groups not formally linked to

the state, it is the first part of the test that is critical.3 The key question

in assessing state responsibility for acts such as 9/11 is therefore whether

the standards for attribution, which derive principally from international

jurisprudence, as recently set out in the International Law Commission’s

Articles on State Responsibility, have been met.

The question of attribution is relatively straightforward where conduct

occurs at the hand of state officials or organs of the state,4 or persons exercising elements of ‘governmental authority’ in accordance with national

law.5 In respect of such persons, states are directly responsible for their

conduct which amounts to an ‘act of state’.6 This is so even if the official

exceeded or acted outside his or her authority.7

2



3



4

5

7



Article 2 of the Articles on Responsibility of States for Internationally Wrongful Acts,

adopted by the International Law Commission in 2001. See Report of the ILC on the work

of its 53rd session, UN Doc. A/56/10 (2001), Chapter IV, pp. 59–365. The text of the ILC’s

Articles on State Responsibility and of the ILC Commentaries thereto are also reproduced in

J. Crawford, The International Law Commission’s Articles on State Responsibility: Introduction, Text and Commentaries (Cambridge, 2002).

If the events of September 11 could be attributable to the state, this second prong of the

test would clearly be satisfied as violence against another state would violate the rules on

the use of force, set out at Chapter 5.

Article 4, ILC’s Articles on State Responsibility.

6

Article 5, ILC’s Articles on State Responsibility.

Ibid.

Article 7, ILC’s Articles on State Responsibility.



state responsibility in international law



49



Somewhat more controversial is the question of the standard for attribution where those directly responsible for conduct are private individuals or groups with no formal relationship with the state. As ‘a transparent relationship between terrorist actors and the state is predictably

uncommon’,8 this is the critical question for assessing state responsibility

for acts of ‘terrorism’. The law governing the standard by which states

may be legally responsible although not formally linked to perpetrators is

described below.9 As explained, on the one hand, it is well established that

states are not strictly responsible for wrongs orchestrated on or emanating from their territory.10 On the other, states are responsible for conduct

over which they exercised effective control.11 Controversy and uncertainty

arises (heightened post 9/11) as to whether lesser forms of involvement,

such as support, ‘harbouring’, encouragement or even passive acquiescence in wrongs is sufficient to render the acts of criminal organisations

attributable to the state.



3.1.1.1 Effective or overall control

International jurisprudence and the work of the International Law Commission support the view that the acts of private individuals may be

attributed to a state which exercises sufficient control over the conduct in

question. According to the International Court of Justice in the Nicaragua

case, the test is whether the state or states in question exercised ‘effective control’.12 Although the Court found the US to have helped finance,

organise, equip, and train the Nicaraguan Contras, this was not sufficient

to render the Contras’ activities attributable to the US. Such a level of

support and assistance did not ‘warrant the conclusion that these forces

[were] subject to the United States to such an extent that any acts they

have committed are imputable to that State’.13 The United States was found

8

9

10



11



12

13



See S. Schiedeman, ‘Standards of Proof in Forcible Responses to Terrorism’, 50 (2000)

Syracuse Law Review 249.

As responsibility turns on a complex evaluation of the facts, the sort of fact scenarios in

which the test has been deemed satisfied, and when not, are also noted below.

See below, para. 1.1.3. See also Oppenheim’s International Law, pp. 502–3, noting that ‘it is

in practice impossible for a state to prevent all injurious acts that a person might commit

against a foreign state . . . accordingly . . . state responsibility for acts of private individuals

is limited’.

Oppenheim’s International Law, p. 501, refers to ‘vicarious responsibility’ though this has

been questioned, see I. Brownlie, Principles of Public International Law, 6th ed. (Oxford,

2003), pp. 431ff.

Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States

of America), Merits, ICJ Reports 1986, p. 14 (hereinafter ‘Nicaragua case’), paras. 86–93.

Ibid.



50



international responsibility and terrorism



liable for specific activities which were proved to be the result of direct

action on the part of its military or foreign nationals in its pay. Despite

controversy surrounding this decision, generated by those who consider

it to impose too rigorous a threshold for establishing responsibility,14 the

Nicaragua ‘effective control’ test remains authoritative. It demonstrates

that attribution must be established vis-` -vis particular conduct (rather

a

than over the group’s actions more generally),15 and that the threshold

for attribution is high.16

The jurisprudence of the Nicaragua case has been developed by the

ICTY.17 Reflecting Nicaragua, the Trial Chamber in the Tadic case noted

that the relationship between the groups and the state must be more than

one of ‘great dependency’, amounting instead to ‘a relationship of control’.18 The Appeals Chamber, while endorsing this, found that different

tests applied in respect of private individuals who are not militarily organised and paramilitary or similar groups.19 In respect of the latter the test

was whether the state exercised ‘overall control’ over the activities of the

group,20 rather than effective control of particular conduct. The Tribunal

again reflected the Nicaragua judgment by emphasising that the ‘mere

provision of financial assistance or military equipment or training’ was

insufficient, requiring instead that the state have ‘a role in organising,

coordinating or planning the military actions’.21

Moreover, the ICTY noted that where the ‘controlling State’ is not

the state where the armed clashes occur, as is the case with Afghanistan

in respect of acts of al-Qaeda in the United States, ‘more extensive and

14



15

16

17



18

19



20



See dissenting judgments (of Judges Jennings and Schwebel) in Nicaragua which considered that ‘substantial involvement’ in the form of financial or military assistance could

suffice, and the discussion of the case in G.M. Travalio, ‘Terrorism, International Law and

the Use of Military Force’, 18 (2000) Wisconsin International Law Journal 145 at 265.

See also ILC’s Commentary to Article 8(3), confirming that state responsibility under the

ILC’s Articles was considered to arise in relation to particular conduct.

See Nicaragua case, paras. 86–93. Nicaragua demonstrated also the evidentiary difficulty

of proving state responsibility for acts of non-state actors.

See Prosecutor v. Tadic, Case No. IT-94-1-A, Judgment (Appeals Chamber), 15 July 1999

(hereinafter ‘Tadic Appeal Judgment’). The question was whether the acts of the VRS

(Bosnian Serb forces) could be imputed to the Government of the Federal Republic

of Yugoslavia (Serbia and Montenegro), such that an international conflict had arisen

between that state and Bosnia-Herzegovina. Note that the question arose for the purpose

of determining individual responsibility for IHL violations, whereas Nicaragua addressed

state responsibility directly.

Tadic Appeal Judgment.

For acts of individuals to be attributed to the state generally requires ‘specific instructions’,

or they may be ‘publicly endorsed or approved ex post facto by the State at issue’. See Tadic

Appeal Judgment, para. 137.

21

Ibid.

Ibid.



state responsibility in international law



51



compelling evidence is required to show that the state is genuinely in

control of the units or groups, not merely by financing and equipping

them, but also by generally directing or helping plan their actions’.22

The ILC’s Articles in turn confirm the high threshold for attributing

acts of private individuals to the state, providing that such acts may be

attributed to the state if the person is acting on ‘instructions’ of the state,

or under the state’s ‘direction or control’.23

In conclusion, while formulae vary slightly, it is well established that

the question is ultimately one of ‘control’. It is a question of degree (and

an issue of fact to be established by those alleging responsibility) ‘whether

the individuals concerned were sufficiently closely associated with the

state for their acts to be regarded as acts of the state rather than as acts of

private individuals’.24



3.1.1.2 Ex post facto assumption of responsibility

Where the state does not exercise the necessary control at the time of

the conduct in question, it may nonetheless assume responsibility for the

wrong ex post facto, where it subsequently ‘acknowledges or accepts’ the

conduct as its own.

In the Tehran Hostages case, the ICJ held that while the ‘direct’ responsibility of Iran for the original takeover of the US Embassy in Tehran in

1979 was not proved,25 subsequent statements in the face of incidents

involving hostage taking by students created liability on the part of the

state.26 To the extent that the judgment indicates that the Iranian State was

considered capable of putting a stop to an on-going situation and instead

chose to endorse and to ‘perpetuate’ it, the Court’s finding against Iran is

consistent with the application of the ‘effective control’ test. But the judgment also makes clear that even if such a test were not met, the state may

become responsible through its subsequent ‘approval’ or ‘endorsement’

of wrongful acts. This approach has been followed by the ICTY27 and, as

noted above, the ILC’s Articles.28

22

24

25



26

28



23

Ibid., para. 138.

Article 8, ILC’s Articles.

Oppenheim’s International Law, p. 550.

See United States Diplomatic and Consular Staff in Teheran (United States v. Iran), ICJ

Reports 1980, p. 3 (hereinafter ‘Teheran Hostages’ case). Note, however that the Court held

that, during the first phase of the occupation of the American Embassy, the international

responsibility of Iran arose from a breach of the different primary obligations of due

diligence. See ibid., pp. 31–3, paras. 63–8 and discussion of due diligence below, this

chapter, para. 1.2.

27

Ibid., p. 35, para. 74.

Tadic Appeal Judgment, para. 137.

Article 11, ILC’s Articles on State Responsibility.



52



international responsibility and terrorism



It should be noted however that what is required goes beyond mere

approval of the conduct of others, to a degree of endorsement whereby

the state can be said to have identified the conduct ‘as its own’.29



3.1.1.3 Insufficiency of territorial link

The rejection of strict liability for a state on whose territory crimes are

orchestrated has been long established, since before Nicaragua. As the

ICJ noted in 1949 in the Corfu Channel case, it is impossible to conclude

‘from the mere fact of the control exercised by a state over its territory

and waters that that State necessarily knew or ought to have known of

any unlawful act perpetrated therein nor that it should have known the

authors’.30 It would, moreover, be anomalous to suggest a strict liability

test in the context of 9/11, potentially implicating the responsibility of

the US, Germany or others in respect of those who trained and organised

on their territories. Likewise, simple knowledge of suspected terrorist

activities, which could potentially implicate many states, would clearly

not itself be enough.

3.1.1.4 A grey area? Harbouring terrorists post 9/11

States are not then strictly responsible for international wrongs emanating from their territory but they are responsible for acts of individuals

or groups over whom they exercise ‘effective control’, or where they subsequently endorse the conduct as their own. Before September 11 it had

been suggested that there was also a difficult ‘grey area’,31 wherein ‘the

issue becomes more difficult when a state, which has the ability to control terrorist activity, nonetheless tolerates, and even encourages it’.32 Post

September 11, this grey area has become both increasingly significant and

increasingly murky.

Immediately following the events of September 11, the US President

asserted that in the search for those ‘responsible’, no distinction would

29



30

31



32



See the ILC’s Commentary to Article 11: ‘as a general matter, conduct will not be

attributable to a State under Article 11 where a State merely acknowledges or expresses its

verbal approval of it’.

Corfu Channel (United Kingdom v. Albania), Merits, ICJ Reports 1949, p. 4.

See A. Cassese, ‘The International Community’s “Legal” Response to Terrorism’, 38 (1989)

ICLQ 589 at 599. Cassese sets out six levels of involvement that a state may have in terrorist

activity. The three grey areas in the middle involve the supply of financial aid or weapons,

logistical or other support and acquiescence, respectively.

Travalio, ‘Terrorism’, at 154.