Terrorism As An Undefined Legal Concept - The Struggle For Consensus In International Law
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Category: International Law
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TERRORISM AS AN UNDEFINED LEGAL CONCEPT: THE
STRUGGLE FOR CONSENSUS IN INTERNATIONAL LAW
Devesh Kumar, Himachal Pradesh National Law University, Shimla
ABSTRACT
Terrorism remains one of the most intensely debated and controversial subjects in international law, despite its frequent appearance in political speeches, legal discussions, and security strategies. This article explores the reasons why an agreed-upon legal definition of terrorism is still missing from international law and explains the complex challenges that have made such an agreement so elusive. It traces the evolution of the concept of terrorism from its origins during the French Revolution, where the term described state violence and political purges, to its modern association with non-state groups, acts of political violence, radical ideologies, and threats to global security.
More recently, terrorism has come to symbolise unpredictable violence targeting civilians, governments, or symbols of authority, often designed to instil fear and achieve political, religious, or ideological aims. The article carefully distinguishes terrorism from related phenomena such as violent extremism, guerrilla warfare, resistance movements, and ordinary criminal acts. It highlights the legal and practical difficulties in identifying not only what constitutes a terrorist act, but also in determining who should be labelled a terrorist. These challenges are compounded by the fact that the same act may be seen as terrorism by some and as legitimate resistance or struggle for freedom by others, depending on perspective, context, and political interests.
The article examines how a patchwork of international treaties, United Nations resolutions, national laws, and global institutions has produced a wide range of legal approaches to terrorism, often leading to inconsistency and confusion. Special attention is given to the reasons behind the world’s failure to adopt a single, comprehensive convention on terrorism. Political disagreements, deep concerns about national sovereignty, and the persistent debate over the line between ‘Terrorist’ and ‘Freedom fighter’ all play central roles in blocking consensus. The article explains how overly broad definitions of terrorism can be misused by authorities, resulting in over-criminalisation, human rights violations, and the suppression of legitimate dissent.
Conversely, definitions that are too narrow may undermine international cooperation, weaken accountability, and allow dangerous acts to go unpunished. Ultimately, the article argues that defining terrorism is not just a technical or legal issue, but a complex struggle
involving law, political power, national interests, and the search for legitimacy on the global stage. Keywords: Terrorism, International Law, Legal Definition, United Nations, Counterterrorism, State Sovereignty, Political Violence, Human Rights
INTRODUCTION
Although terrorism is frequently invoked in adversarial political discourse, there remains no international consensus regarding its precise definition. 1 This paper revisits and reviews key conceptual approaches from academia, government, and international organisations to clarify the concept of terrorism, examine the absence of a universally accepted definition, and analyse the underlying reasons for this lack of consensus. 2 Recently, the destruction of the underwater pipeline in the North Sea was labelled an act of terrorism by Vladimir Putin. 3 Similarly, when supporters of Donald Trump stormed the US Capitol, some US observers described this event as terrorism. 4 These examples illustrate that terrorism remains a contested concept, as reflected in the adage, ‘One man’s terrorism is the other man’s freedom fighter.
’5 A central issue concerns the authority to use violence and the intended targets, as terrorists frequently attack strangers and unarmed individuals. 6 This characteristic renders terrorist violence particularly perplexing and often leads to confusion between violent extremism and terrorism, despite the fact that these concepts are distinct. 7 For instance, while Osama Bin Laden is widely recognised as a terrorist, he and his organisation considered their actions to be justified, framing them as a form of ‘good terrorism’. 8 This perspective suggests that Bin Laden believed he was engaged in a just war; consequently, his followers viewed him as a violent extremist with a cause, whereas the broader international community regarded him as a terrorist. 9 This paper examines a specific aspect of terrorism, focusing on the legal and non-legal challenges related to its definition.
It analyses how various terrorist acts, international conventions, and protocols have
1 Carlile, Alex. The Definition of Terrorism: A Report. Stationery Office, 2007.
2 Ibid.
3 Putin Calls “sabotage” against Nord Stream an “Act of International Terrorism” -Kremlin | Reuters,
www.reuters.com/world/putin-calls-sabotage-against-nord-stream-an-act-international-terrorism-kremlin-2022- 09-29/. Accessed 26 May 2026. 4 Episode 44: Capitol Insurrection, Riot, or Domestic Terrorism? | American University, Washington, DC, www.american.edu/sis/big-world/44-capitol-insurrection-riot-or-domestic-terrorism.cfm. Accessed 26 May 2026.
5 Schmidt, Alex P. Defining Terrorism, 13 Mar. 2023, doi:10.19165/2023.3.01.
6 Ibid, at page. 3
7 Ibid.
8 Ibid.
9 Ibid.
contributed to the refinement of the understanding of the term. A detailed overview of the origin and evolution of the term ‘Terrorism’
The historical roots of the term ‘terror’ can be traced to Latin, with additional origins in Sanskrit and Russian. Across these languages, the term consistently refers to concepts such as fright, death, dismay, and alarm. 10 Furthermore, the suffix ‘ism’ typically denotes a political philosophy, as in liberalism and socialism, or may indicate a practical application. 11 In 1793, the revolutionary government of France faced threats from aristocrats and members of the upper class who conspired with foreign rulers to restore the ancien régime. In response, the National Convention, led by the Jacobins, declared that ‘terror is the order of the day’ and called for the widespread use of the infamous guillotine throughout France to consolidate the revolution. 12 Maximilien Robespierre13 led the Reign of Terror in France.
14 Over time, the situation deteriorated, resulting in numerous executions and killings. 15 Eventually, Robespierre himself feared for his life and ultimately became a victim of the revolution he had helped to lead. The term ‘terrorism’, which initially referred to the abuse of power, became widespread and reached England, where it was popularised by the English writer Edmund Burke in his work. 16 Since 1794, the definition of terrorism has evolved significantly, reflecting a shift from state actors to non-state actors as primary perpetrators. 17 The guillotine, once emblematic of regime terrorism, was supplanted in the latter half of the nineteenth century by the use of bombs. 18 This transition was facilitated by Alfred Nobel’s invention of dynamite in the 1860s, which contributed to the emergence of the ‘philosophy of the bomb’.
Anarchists and social revolutionaries adopted this approach to attract public attention, culminating in the use of
10 Defining Terrorism: Insights from Schmid’s Analysis (ICCT Report) - Studocu,
www.studocu.com/in/document/university-of-delhi/political-science/reading-on-terrorism-schmidt-definingterrorism-1/95167058. Accessed 28 May 2026.
11 Ibid, at page. 4
12 Ibid.
13 Butow, Evan. “From Idealist to Tyrant: The Life of Maximilien Robespierre.” Chronos: The Syracuse
University Undergraduate History Journal, vol. 15, no. 1, Sept. 2024, pp. 33–40, doi:10.14305/jn.29975174.15.1.4.
14 Ibid, at page. 35
15 Fraser, Hugh. “The Tyranny of Terrorism.” International Terrorism: Challenge and Response, 29 Sept. 2020, pp. 23–32, doi:10.1201/9781003073208-5. 16 “Political Terrorism: A Research Guide to Concepts, Theories, Databases and Literature. Edited by Alex P. Schmid. (New Brunswick, N.J.: Transaction Books, 1984. Pp. XIV + 585. $34.95.” American Political Science Review, vol. 78, no. 4, Dec. 1984, pp. 1211–1225, doi:10.2307/1955989.
17 Supra, note. 13 at page. 37
18 Ibid.
propaganda. As Alexander Berkman19 famously stated, ‘Terrorism was considered a means of avenging a popular wrong, inspiring fear in the enemy, and also calling attention to the evil against which the act of terror was directed’. 20 Over time, terrorism has evolved into a complex phenomenon. Monty G. Marshall21 and Ted R. Gurr22 observe that Terrorism, as a political act, stands at the nexus of individual and collective action, the emotional and the rational, the conventional and the unconventional. It can be the strongest form of protest, the weakest form of rebellion, or a specialised tactic in a broader process of tyranny or warfare. 23 Terrorism can be classified according to several typologies.
24 Perpetrator-centred typologies include regime repressive state terrorism, non-state terrorism, anarchist terrorism, socialrevolutionary left-wing terrorism, racist or xenophobic right-wing terrorism, ethno-nationalist separatist or irredentist terrorism, vigilante revenge terrorism, lone wolf or lone actor terrorism, organised crime-related narco-terrorism, and state-sponsored foreign terrorism. 25 Methods and tactics-centred typologies encompass insurgent civil war terrorism, inter-state war terrorism, nuclear terrorism, suicide terrorism, sexual terrorism, and cyber terrorism. 26 Motivationcentred typologies refer to political terrorism, revolutionary terrorism, religious fundamentalist terrorism, the terrorism, eco-terrorism, single-issue terrorism, and idiosyncratic terrorism, such as that related to mental illness.
27 Another classification is location-centred typology, which includes domestic (national) terrorism, urban terrorism, transnational terrorism, and international terrorism. 28 The challenge of formulating a definition of terrorism that encompasses all forms of politically motivated violence is formidable. 29 Some acts, although widely labelled as terrorism, may be misclassified. Achieving commonalities requires a high level of abstraction, which often results in overly broad and vague definitions. 30
19 “Alexander (Sasha) Berkman (1870-1936).” PBS, Public Broadcasting Service,
www.pbs.org/wgbh/americanexperience/features/goldman-alexander-sasha-berkman-1870-1936/. Accessed 02 June 2026.
20 Supra, note. 5 at page. 5
21 “Monty G. Marshall: BIOS.” The Cipher Brief, www.thecipherbrief.com/experts/monty-g-marshall. Accessed
03 June 2026.
22 “In Memory of Ted Gurr.” Center for International Development and Conflict Management,
cidcm.umd.edu/research/memory-ted-gurr. Accessed 03 June 2026.
23 Supra, note. 5 at page. 5
24 Marsden, Sarah V., and Alex P. Schmid. “Typologies of Terrorism and Political Violence.” The Routledge Handbook of Terrorism Research, doi:10.4324/9780203828731.ch3.
25 Ibid.
26 Ibid.
27 Ibid.
28 Ibid.
29 Ibid.
30 Ibid.
Defining the Characteristics of a Terrorist Act and the Profile of a Terrorist Rather than defining ‘terrorism’, the focus could be on the terrorist act itself. This approach, which looks at the terrorist crime, has been used by many Western governments and by several conventions and agreements adopted by the United Nations General Assembly31. The range of terrorist crimes has gradually expanded to include early actions like encouraging and praising terrorism, making threats of terrorist attacks, funding, recruiting, training, and being a member of an organisation that carries out terrorist acts. 32 However, defining a terrorist attack is not an easy or simple task. 33 Take hijacking, for example, which is widely seen as the most common terrorist crime.
But hijacking is divided into two types: one where the hijacking is just to escape, and another where it is to blackmail a third party, while both types are crimes and cause fear, only the second is truly terrorist. 34 Since 1963, UN member states have signed and approved 19 international agreements to deal with crimes often seen as terrorist acts. These specific agreements, made through the United Nations, the International Civil Aviation Organisation (ICAO)35, the International Maritime Organisation (IMO)36, and the International Atomic Energy Agency (IAEA)37, list certain offences as crimes. However, these are called unlawful acts instead of terrorist acts, except for terrorist bombings. Still, these agreements are usually called anti-terrorist conventions and protocols:
1. 1963 Convention on Offences and Certain Other Acts Committed on Board Aircraft38;
2. 1970 Convention for the Suppression of Unlawful Seizure of Aircraft39;
3. 1971 Convention for the Suppression of Unlawful Acts against the Safety of Civil
31 “United Nations, Main Body, Main Organs, General Assembly.” United Nations, www.un.org/en/ga/.
Accessed 05 June 2026.
32 Supra, note. 5 at page. 10
33 Id, at page. 11
34 Ibid.
35 “International Civil Aviation Organization.” Home, www.icao.int/. Accessed 05 June 2026.
36 International Maritime Organization, www.imo.org/. Accessed 05 June 2026.
37 International Atomic Energy Agency | Atoms for Peace and Development, www.iaea.org/. Accessed 05 June 2026. 38 Convention on Offences and Certain Other Acts Committed On, treaties.un.org/doc/db/terrorism/conv1english.pdf. Accessed 05 June 2026. 39 “UNTC.” United Nations, treaties.un.org/pages/showDetails.aspx?objid=0800000280112834. Accessed 05 June 2026.
Aviation40;
4. 1973 Convention on the Prevention and Punishment of crimes against internationally
protected persons, including Diplomatic Agents41;
5. 1979 international convention against the taking of hostages42;
6. 1980 convention on the physical protection of nuclear material43;
7. 1988 protocol for the suppression of unlawful acts against the safety of maritime
navigation44;
8. 1988 Protocol for the Suppression of Unlawful Acts against the Safety of Fixed
Platforms Located on the Continental Shelf45;
9. 1991 Convention on the marking of plastic explosives for detection46;
10. 1997 International Convention for the Suppression of terrorist bombings47;
11. 1999 International Convention for the Suppression of the Financing of terrorism48;
12. 2005 International Convention for the Suppression of Acts of nuclear terrorism49;
40 No. 14118 Multilateral, treaties.un.org/doc/Publication/UNTS/Volume%20974/volume-974-I-14118english.pdf. Accessed 05 June 2026.
41 Convention on the Prevention and Punishment of Crimes Against,
legal.un.org/ilc/texts/instruments/english/conventions/9_4_1973.pdf. Accessed 05 June 2026. 42 International Convention against the Taking of Hostages, treaties.un.org/doc/db/terrorism/english-18-5.pdf. Accessed 05 June 2026.
43 V.03-85663 (E) Legislative Guide to the Universal Anti-Terrorism,
www.unodc.org/pdf/crime/terrorism/explanatory_english2.pdf. Accessed 05 June 2026. 44 “Convention for the Suppression of Unlawful Acts against the Safety of Maritime Navigation, Protocol for the Suppression of Unlawful Acts against the Safety of Fixed Platforms Located on the Continental Shelf.” International Maritime Organization, www.imo.org/en/about/conventions/pages/sua-treaties.aspx. Accessed 05 June 2026. 45 “Protocol for the Suppression of Unlawful Acts against the Safety of Fixed Platforms Located on the Continental Shelf (1988).” :, www.unodc.org/cld/en/treaties/status/iceland/protocol_for_the_suppression_of_unlawful_acts_against_the_safe ty_of_fixed_platforms_located_on_the_continental_shelf_1988.html. Accessed 05 June 2026. 46 Convention on the Marking of Plastic Explosives for Detection, treaties.un.org/doc/db/terrorism/conv10english.pdf. Accessed 05 June 2026.
47 “International Convention for the Suppression of Terrorist Bombings.” United Nations,
www.un.org/law/cod/terroris.htm. Accessed 05 June 2026.
48 International Convention for the Suppression of the Financing of Terrorism,
treaties.un.org/doc/db/terrorism/english-18-11.pdf. Accessed 05 June 2026.
49 International Convention for the Suppression of the Financing of Terrorism,
13. 2005 amendment to the Convention on the Physical Protection of Nuclear Material50;
14. 2005 protocol to the convention for the suppression of unlawful acts against the safety
of maritime navigation51
15. 2005 protocol to the protocol for the suppression of the unlawful acts against the safety
of fixed platforms located on the continental shelf52;
16. 2010 Convention on the Suppression of Unlawful Acts relating to International Civil
Aviation53
17. 2010 protocol supplementary to the convention for the suppression of unlawful seizure
of aircraft54
18. 2014 protocol to the convention on offences and certain other r acts committed on board
aircraft.55 Some of these specific treaties address illegal acts that people do not usually associate with terrorism. An alternative approach to the definitional challenge is to consider which individuals or groups should be designated as terrorists.56 It is necessary to distinguish terrorists from soldiers, treaties.un.org/doc/db/terrorism/english-18-11.pdf. Accessed 05 June 2026.
50 Convention on the Physical Protection of Nuclear Material (CPPNM) and Its Amendment | IAEA,
www.iaea.org/publications/documents/conventions/convention-physical-protection-nuclear-material-and-itsamendment. Accessed 05 June 2026.
51 Protocol of 2005 to the Convention for the Suppression Of,
sherloc.unodc.org/cld/uploads/res/treaties/definitions/treaty/protocol_to_the_convention_for_the_suppression_o f_unlawful_acts_against_the_safety_of_maritime_navigation_2005_html/Protocol_to_Maritime_Convention_E. pdf. Accessed 05 June 2026.
52 Protocol of 2005 to the Protocol for the Suppression Of,
www.unodc.org/cld/uploads/res/treaties/definitions/treaty/protocol_to_the_protocol_for_the_suppression_of_un lawful_acts_against_the_safety_of_fixed_platforms_located_on_the_continental_shelf_2005_html/Protocol_to_ Fixed_Platform_Protocol_E.pdf. Accessed 05 June 2026. 53 “Convention on the Suppression of Unlawful Acts Relating to International Civil Aviation (2010).” :, www.unodc.org/cld/en/treaties/status/australia/convention_on_the_suppression_of_unlawful_acts_relating_to_i nternational_civil_aviation_2010.html. Accessed 05 June 2026.
54 Protocol Supplementary to the Convention for The,
www.unodc.org/cld/uploads/res/treaties/definitions/treaty/protocol_supplementary_to_the_convention_for_the_ suppression_of_unlawful_seizure_of_aircraft_2010_html/Protocol_to_Unlawful_Seizure_Convention_E.pdf. Accessed 05 June 2026.
55 Consolidated Text of the Convention on Offences and Certain ...,
www.unodc.org/documents/terrorism/News%20and%20Events/Consolidated_Text_1963_Tokyo_Convention- 2014_Montreal_Protocol_ENG.pdf. Accessed 05 June 2026. 56 Aldrich, George H. “The Laws of War on Land.” American Journal of International Law, vol. 94, no. 1, Jan.
freedom fighters, guerrillas, and resistance fighters. 57 Similar to how a soldier who adheres to the laws of war may become a war criminal, a guerrilla, resistance fighter, partisan, or other irregular combatant may also be classified as a terrorist if they employ violence against civilians. 58 For instance, if a soldier or military unit primarily utilises lawful conventional and guerrilla tactics but occasionally engages in acts of terrorism, it is unclear whether they should be identified as soldiers, insurgents, or terrorists. The criteria for drawing this distinction remain contested. 59 It is widely understood that no one is born a terrorist. 60 The reasons why someone becomes involved in terrorism are complex and often include both personal and situational factors. Young people, in particular, may be drawn into terrorism for many reasons.
Researchers have found that there is not just one personality type that is more likely to become a terrorist, but rather several traits that can increase the risk, especially in certain political and social environments. 61 A person's involvement in terrorism or with a terrorist organisation can take many forms. 62 These include promoting or supporting terrorism through demonstrations, mass media, or the internet; helping terrorists gather information or spread propaganda; providing false testimony or an alibi for someone accused of terrorism; offering services such as a safe house; donating money; helping with recruitment and training; supplying identity papers; giving expert advice or intelligence; assisting with logistics and transportation; obtaining weapons or bomb-making materials; and supporting terrorist operations.
Some people may act alone on behalf of a terrorist group, while others join such groups directly. 63 Rogue states may conceal their involvement by operating through terrorist front organisations, as exemplified by Hezbollah, which functions both as an instrument of Iranian intelligence and as part of the Lebanese government. 64 Few major terrorist organisations can survive for 2000, pp. 42–63, doi:10. 2307/2555230.
57 Ibid.
58 Ibid.
59 Ibid.
60 Schmid, Alex. “Public Opinion Survey Data to Measure Sympathy and Support for Islamist Terrorism: A Look at Muslim Opinions on Al Qaeda and Is.” Terrorism and Counter-Terrorism Studies, 2017, doi:10.19165/2017.1.02.
61 Ibid.
62 Ibid.
63 Ibid.
64 Sumbatova, Nina R. “Greville G. Corbett, Agreement. (= Cambridge Textbooks in Linguistics). Cambridge: Cambridge University Press, 2006. XVIII + 328PP. ISBN-10 0-521-00170-6, ISBN-13 978-0-521-001770-0 (Paperback), ISBN-10 0-521-80708-5, ISBN-13 978-0-521-80708-1 (Hardback).” Word Structure, vol. 3, no. 2, Oct. 2010, pp. 264–274, doi:10.3366/word.2010.0009.
extended periods without clandestine state support. Currently, there is a lack of internationally agreed legal instruments for designating states as sponsors of terrorism. 65 Although some terrorists act alone, often referred to as lone wolves, the majority are affiliated with clandestinely operating terrorist groups. 66 Brian Phillips defines terrorist groups as subnational political organisations that use terrorism. 67 Generally, governments and international organisations have found it easier to designate certain non-state actors and specific acts of politically motivated violence as terrorism than to reach consensus on a precise definition of terrorism. 68 Comprehensive Definitions of Terrorism by Various National Governments and the United Nations Governments possess significant authority to shape the definition of terrorism within their jurisdictions.
Most national governments establish their own, often detailed, definitions, while some classify acts of terrorism as ordinary, non-political crimes. 69 The specific definition adopted frequently depends on whether comprehensive counterterrorism legislation exists in the country. 70 For instance, the United Kingdom’s Terrorism Act 200071 provides an extensive and nuanced definition, building on the original British legislation,72 the Prevention of Terrorism Act 197473. The 1974 Act74, introduced during the Troubles in Northern Ireland, defined terrorism in broad terms as the use of violence for political ends and included any act of violence intended to instill fear in the public or any segment thereof. In contrast, the Terrorism Act 200075 and its subsequent amendments in 200676, 201977, and 202178 expanded
65 Ibid, at page. 266
66 Ibid.
67 Phillips, Brian J. “What Is a Terrorist Group? Conceptual Issues and Empirical Implications.” Terrorism and Political Violence, vol. 27, no. 2, 25 Feb. 2014, pp. 225–242, doi:10.1080/09546553.2013.800048.
68 Ibid.
69 Supra, note. 5 at page. 17
70 Ibid.
71 Participation, Expert. “Terrorism Act 2000.” Legislation.Gov.Uk, Statute Law Database,
www.legislation.gov.uk/ukpga/2000/11/contents. Accessed 08 June 2026.
72 Ibid.
73 Prevention of Terrorism (Temporary Provisions) Act 1974,
www.legislation.gov.uk/ukpga/1974/56/contents/enacted. Accessed 08 June 2026.
74 Ibid.
75 Supra, note. 71
76 Participation, Expert. “Terrorism Act 2006.” Legislation.Gov.Uk, Statute Law Database,
www.legislation.gov.uk/ukpga/2006/11/contents. Accessed 08 June 2026. 77 Participation, Expert. “Counter-Terrorism and Border Security Act 2019.” Legislation.Gov.Uk, Statute Law Database, www.legislation.gov.uk/ukpga/2019/3/contents. Accessed 08 June 2026. 78 Participation, Expert. “Counter-Terrorism and Sentencing Act 2021.” Legislation.Gov.Uk, Statute Law Database, www.legislation.gov.uk/ukpga/2021/11/contents. Accessed 09 June 2026.
and refined the legal framework, reflecting the evolving nature of terrorist threats and government responses. 79 This demonstrates that legal definitions of terrorism are not static; they can be revised and adapted as new types of threats emerge and as political contexts shift. 80 Some governments, recognising the complexity of terrorism, maintain several distinct definitions to address different aspects or manifestations of the phenomenon. 81 For example, the United States government has historically maintained more than twenty separate definitions, each tailored to address specific contexts such as domestic terrorism, international terrorism, terrorist activity, acts of terrorism, and federal crimes of terrorism.
82 While some of these definitions share common language and criteria, others vary significantly, illustrating the diverse perspectives and priorities that influence national legal frameworks. 83 The United Nations is the world’s largest international organisation, bringing together 193 countries to work on global issues. 84 Because of its size and role, people often look to the UN to set the standard for what counts as international terrorism but reaching an agreement within the UN can be difficult, as member countries have very different views and interests. 85 The UN’s Security Council, which is its most influential group, started talking about terrorism back in 1985. 86 However, it wasn’t until after the tragic events of September 11, 2001, that fighting terrorism became a top priority, after those attacks, the Security Council passed Resolution
137387. This required all UN countries to take steps like making it illegal to fund terrorist
groups, stopping terrorist organisations from operating, keeping terrorists from moving from place to place, and making sure those responsible are brought to justice. Still, the Security Council never gave a clear, simple definition of what terrorism actually is, so each country is left to decide for itself.88 The most detailed and sustained effort to define terrorism at the international level has been led by a group of 35 legal experts within the ad hoc committee of the United Nations legal
79 Ibid.
80 Supra, note. 5 at page. 18
81 Ibid.
82 Benedek, Wolfgang. Transnational Terrorism, Organized Crime and Peace-Building: Human Security in the Western Balkans. Palgrave Macmillan, 2010.
83 Ibid.
84 Saul, Ben. Defining Terrorism in International Law. Oxford University Press, 2011.
85 Ibid.
86 Ibid.
87 United Nations S/RES/1373 (2001) Security Council Distr.: General,
www.unodc.org/pdf/crime/terrorism/res_1373_english.pdf. Accessed 09 June 2026.
88 Supra, note. 84
Committee (6th Committee) of the General Assembly. 89 This committee was established specifically to address the complex challenge of developing legal tools to combat terrorism worldwide. 90 From 1997 to 2005, the committee made significant progress by drafting and finalising three important conventions: the International Convention for the Suppression of Terrorist Bombings (1997)91, the International Convention for the Suppression of the Financing of Terrorism (1999)92, and the International Convention for the Suppression of Acts of Nuclear Terrorism (2005)93. Each of these conventions aimed to address specific forms of terrorist activity, creating clear legal obligations for countries to prevent, criminalise, and prosecute such acts94. Despite these achievements, the committee struggled to reach agreement on a single, comprehensive convention against international terrorism.
India first proposed this convention in 1996, hoping for an all-encompassing legal definition and framework. 95 Yet, more than twenty-five years later, the draft has still not been approved by the General Assembly, the main obstacle has been the inability to agree on what should be included in the definition of terrorism. According to scholar Eva Herschinger96, this ongoing disagreement is rooted in the tension between protecting national sovereignty and serving the universal interests of the international community. 97 In other words, each country wants to retain the power to define terrorism according to its own political and legal considerations, and is wary of accepting a global definition that could limit this authority98. As she notes, “What counts as a terrorist offence is highly dependent on national interests and a universally accepted definition is thus 89 Rosand, E.
“Security Council Resolution 1373 and the Counter-Terrorism Committee: The Cornerstone of the United Nations Contribution to the Fight against Terrorism. ” Legal Instruments in the Fight Against International Terrorism, 1 Jan. 2004, pp. 603–631, doi:10. 1163/9789047413509_023.
90 Ibid.
91 1997 International Convention for the Suppression Of ...,
www.unodc.org/documents/treaties/Special/1997%20International%20Convention%20for%20the%20Suppressi on%20of%20Terrorist.pdf. Accessed 09 June 2026.
92 1999 International Convention for the Suppression of The ...,
www.unodc.org/documents/treaties/Special/1999%20International%20Convention%20for%20the%20Suppressi on%20of%20the%20Financing%20of%20Terrorism.pdf. Accessed 09 June 2026.
93 “UN, United Nations, UN Treaties, Treaties.” United Nations,
treaties.un.org/pages/ViewDetailsIII.aspx?src=TREATY&mtdsg_no=XVIII- 15&chapter=18&Temp=mtdsg3&clang=_en. Accessed 09 June 2026.
94 Supra, note. 89
95 Bakker, Edwin. Terrorism and Counterterrorism Studies: Comparing Theory and Practice. Project Muse, Distributed in North America by the University of Chicago Press Leiden University Press, 2016.
96 Long read by Joana Cook, et al. “Eva Herschinger.” ICCT, 20 Nov.
2024, icct.nl/people/eva-herschinger. Accessed 09 June 2026. 97 Herschinger, Eva. “A Battlefield of Meanings: The Struggle for Identity in the UN Debates on a Definition of International Terrorism.” Terrorism and Political Violence, vol. 25, no. 2, Apr. 2013, pp. 183–201, doi:10.1080/09546553.2011.652318.
98 Ibid.
considered to delimit sovereign power since it entails giving up the right to define terrorism according to one’s own rationale. 99” This highlights how deeply political and sensitive the process of defining terrorism remains at the global level. Conclusio Many people argue that reaching a single, universally accepted definition of terrorism is nearly impossible. 100 This difficulty arises not because experts lack the legal or social tools to define it, but because the concept of terrorism is deeply political and emotionally charged. Governments and powerful groups often shape the definition to suit their own interests, using it to legitimise their actions or discredit their opponents. 101 What one country calls terrorism, another might see as a fight for freedom or justice.
These conflicting perspectives reflect the complex realities of both domestic and international politics, where nations defend their own positions and narratives102. As a result, efforts to agree on a definition are often stalled by debates over whose interests and values should take precedence. This ongoing struggle highlights how the term 'terrorism' remains one of the most contested and debated concepts in global affairs. 103 Terrorism as a concept and practice has evolved dramatically since the term was first coined during the French Revolution in the 1790s. 104 In its earliest usage, terrorism described the violent tactics employed by the revolutionary government to maintain control and suppress opposition. 105 Over the centuries, the meaning has expanded to include a wide range of violent acts aimed at achieving political, ideological, or religious goals.
106 The evolution of terrorism has closely followed changes in technology, weaponry, and communication. For example, the development of explosives and firearms in the 19th and 20th centuries enabled smaller groups to inflict greater harm, while advances in global communication and mass media have allowed terrorist acts to reach and influence audiences far beyond their immediate targets. 107
99 Ibid.
100 Van der Wilt, Harmen, and Christophe Paulussen. “The Role of International Criminal Law in Responding to the Crime–Terror Nexus.” European Journal of Criminology, vol. 16, no. 3, 25 Feb. 2019, pp. 315–331, doi:10.1177/1477370819828934.
101 Ibid, at page. 322
102 Ibid.
103 Ibid, at page. 330
104 Supra, note. 13 at page. 31
105 Ibid.
106 Supra, note. 5
107 Ibid.
Philosopher Friedrich Nietzsche108 once observed, “All concepts in which an entire process is semiotically concentrated elude definition, only that which has no history is definable. ”109 This insight is especially relevant to terrorism, a concept with a long and complex history that resists simple definition. Despite this, scholars and policymakers continue to refine and debate what qualifies as terrorism. 110 Today, some scholars distinguish between ‘old’ and ‘new’ terrorism, often using the September 11, 2001 attacks as a dividing line. Old terrorism, typically associated with nationalist or separatist movements, was often geographically limited and sought specific political concessions. 111 In contrast, new terrorism is seen as more transnational, ideologically driven, and indiscriminate in its use of violence, sometimes aiming for mass casualties and widespread fear.
However, while these distinctions are useful for analysis, many experts argue that the similarities between old and new terrorism, such as their reliance on violence to further a cause and their strategic use of fear, are ultimately greater than the differences. 112 Terrorism is often defined in broad, sweeping terms rather than with specific, narrow criteria. While a broad definition might seem practical for capturing a wide range of violent acts, it can actually create significant problems in practice. 113 For instance, after the 9/11 attacks, the phrase ‘global war on terror’ was used to justify a massive expansion of counterterrorism efforts. This approach not only demanded enormous resources but also allowed authorities to stretch the label of terrorism to cover activities that may have only loosely fit the original intent.
As a result, peaceful protestors, political opponents, or minority groups could sometimes be unjustly targeted under the guise of fighting terrorism114 and such overreach increases the risk of human rights abuses, erodes civil liberties, and can even fuel resentment or radicalisation among affected communities. On the other hand, using a much narrower definition of terrorism, one that focuses only on 108 Anderson, R. Lanier. “Friedrich Nietzsche. ” Stanford Encyclopedia of Philosophy, Stanford University, 19 May 2022, plato. stanford. edu/entries/nietzsche/. Accessed 11 June 2026. 109 Hatab, Lawrence J. Nietzsche’s on the Genealogy of Morality: An Introduction. Cambridge University Press, 2008.
110 Ibid.
111 Supra, note. 5
112 Ibid.
113 Abrahms, Max Benjamin. Rules for Rebels: The Science of Victory in Militant History. Oxford University Press, 2018.
114 Ibid.
certain acts or motivations, means that fewer incidents fall under the term.115 This can help prevent misuse of the label and make it easier for countries to find common ground on what terrorism should mean in international law. With a clear and precise definition, laws can be better targeted, enforcement more accountable, and international cooperation more effective. The importance of getting this definition right cannot be overstated.116 If leading Western policymakers had more carefully considered the consequences of a broad definition before launching the global war on terror, the international response after 9/11 might have been more measured, proportional, and just. This highlights why clarity and precision in defining terrorism are essential for both protecting society and upholding the rule of law.
115 Ibid.
116 Ibid.
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