In contemporary conflicts, both states and non-state actors invoke legal principles to present their violence as necessary and legitimate. Yet they do so within an asymmetric framework: counterterrorism has been extensively institutionalized within international law, while terrorism remains without a universally accepted definition. This gap leaves considerable room for political manipulation. States can cast their opponents’ actions as terrorism while presenting their own as lawful self-defense, and non-state actors turn to principles of resistance and self-determination to contest that distinction. The same act can thus be condemned as ‘terrorism’ by one side and defended as legitimate resistance by the other. This helps sustain cycles of violence where each actor can use the other’s violence to justify its own.

The Legitimacy Gap: Terrorism vs. Counter-Terrorism

“The use of force in self-defense has become increasingly contentious.” States routinely invoke Article 51 of the UN Charter to justify military operations against non-state actors, and since 9/11, this has evolved into a form of “weaponized counterterrorism.” By framing their interventions as necessary responses to terrorism, governments have attempted to broaden the scope of the lawful use of force. Today, counterterrorism functions as a legally sanctioned regime: built on Security Council Resolution 1373 (2001) – which established the Counter-Terrorism Committee (CTC) – reinforced by the UN Global Counter-Terrorism Strategy (A/RES/60/288), and continually reaffirmed through biennial General Assembly review resolutions (e.g. A/RES/62/272, 66/282, 70/291), it provides states with a recognized legal basis to justify the use of force against non-state actors.

Terrorism, by contrast, lacks a comprehensive definition. Despite decades of negotiations, states have failed to reach a consensus on what constitutes terrorism. At the core of the deadlock is whether the activities of state armed forces fall outside the convention, and whether national liberation movements are exempt. The impasse is fundamentally political rather than technical: adopting a comprehensive definition could expose states to accusations that some of their own practices – including military interventions, targeted killings, and occupation policies – could fall under the same label they apply to their adversaries. To avoid this, the United Nations has relied on sector-specific conventions, addressing forms of political violence such as hijacking, hostage-taking, bombings, and terrorist financing, while deliberately leaving terrorism itself undefined. This has produced a fragmented framework with no common legal threshold and no coherent mechanism for collective accountability. Because these conventions treat terrorism strictly as a criminal offense, responsibility is confined to individuals rather than groups, ensuring that neither states nor armed groups can be held accountable as collective actors under international law. 

This asymmetry produces a deep legitimacy gap. Counterterrorism benefits from legal solidity: it is reinforced by UNSC resolutions and institutional monitoring that provide governments with a stable legal basis to frame the use of force as legitimate. By contrast, terrorism remains an open-ended political designation, flexible enough to be stretched, contested, or strategically applied to consolidate authority and delegitimize opponents. When the definition of terrorism is fluid, so is the boundary between lawful and unlawful violence. States typically justify their actions through security and self-defense, while non-state actors ground theirs in resistance and self-determination. Each casts the other as terrorist, turning legality into a tool of normative justification rather than a shared standard. 

Competing Behaviours for Legitimacy: Cycles of Violence 

States often exploit the definitional ambiguity around terrorism to consolidate their authority. By framing their own operations as lawful self-defense under Article 51 while designating non-state armed groups as terrorists, they expand their discretion to suppress political opposition. On this basis, India’s Unlawful Activities (Prevention) Act (UAPA) and Turkey’s Anti-Terror Code enable the designation of Kashmiri separatist groups and Kurdish political actors as terrorist entities. In both cases, claims of self-defense against “terrorist threats” entrench counterterrorism regimes and recast political conflicts as security crises. 

National-liberation movements (NLM) and armed resistance groups, in turn, reject definitions that would criminalize their actions. Palestinian armed groups describe their actions as resistance to occupation; Kashmiri separatist groups invoke anti-colonial protections; and Kurdish movements justify armed resistance as a response to state repression and exclusion. Many states have indeed argued that struggles against colonial domination, foreign occupation, or oppressive regimes should not be treated as terrorism. This view, reflected in the broad acceptance that NLMs are entitled to greater leeway under international law¹, creates a competing source of legitimacy and allows non-state actors to operate according to their own criteria. Without a shared reference point, the same event – a strike, an armed confrontation, a blockade – can be read as terrorism by one side and legitimate resistance by the other. When every actor portrays its violence as a response rather than an initiation, escalation becomes structurally inevitable. Each side embeds its narrative of retaliation so deeply that renewed violence becomes the only viable option, leaving little room for restraint. 

Crucially, many of the actors most frequently designated by Western states did not originate as transnational security threats. They emerged as grassroots political and social movements grounded in local grievances and governance failures. The Muslim Brotherhood built mass support through welfare networks and political mobilization under authoritarian rule; Hamas developed out of this infrastructure in Gaza and combined social provision with armed resistance to occupation; and Hezbollah formed during the Lebanese civil war as a political-military movement filling vacuums left by a collapsing state. Their authority rests not only on coercion, but also on their capacity to deliver services, represent marginalized constituencies, and perform governance functions. As a result, designating a group as terrorist carries far-reaching consequences in fragile states. Cutting off financial channels, external contacts, or political legitimacy ultimately harms the civilian populations that rely on their welfare and governance structures.

The Politics of Terrorism Designation

Terrorism designations most often reflect prevailing ideological biases and the strategic preferences of Western states. Since 9/11, Western governments have focused almost exclusively on Islamist organizations. Although some jurisdictions, including Canada and the United Kingdom, have added far-right and white supremacist groups to their terrorist lists, these additions remain limited in scope. The United States, for instance, has not designated any far-right organization as a Foreign Terrorist Organization (FTO). This imbalance reinforces a security narrative in which Islamist actors are treated as the primary systemic threat, while other forms of political violence are framed as domestic or episodic. Within this hierarchy, Islamist violence is readily classified as terrorism, while comparable violence by other actors faces no such presumption.

Once this narrative is entrenched, terrorism designations operate as a tool for signaling alliances and organizing regional hierarchies. A designation alters an actor’s legal and political status by restricting financial access, constraining diplomatic engagement, and delegitimizing its domestic political role. Conversely, the absence of a designation may function as implicit support, enabling military cooperation or political protection. These decisions shape regional alignments by elevating certain actors and isolating others according to the geopolitical interests of Western states.

For instance, Cuba has long carried a terrorism designation despite lacking “credible evidence”, as reported by Biden Administration officials in 2025. This most likely reflects Washington’s strategic aim to weaken its communist government rather than a response to genuine security threats. Similarly, recent efforts to classify branches of the Muslim Brotherhood as terrorist organizations rest on weak evidence, as there is no credible indication that the group employs violence for political ends. Saudi Arabia, by contrast, has never been considered for designation, regardless of extensive documentation linking  it to al-Qaeda support networks, prior to the September 11 attacks. Here, its strategic value as a major arms recipient and potential candidate for a NATO‑like defense guarantee has shielded it from censure.

Conclusion 

The changing nature of war has moved beyond traditional state-to-state conflict into asymmetric struggles with non-state actors. In this context, the absence of a universal definition of terrorism allows states to act selectively, often guided by ideology and geopolitical interests, while expanding their authority under the banner of counterterrorism. Terrorism designations become a powerful tool used to delegitimize non‑state actors while legitimizing state force. This ambiguity entrenches cycles of violence, blurs the line between legality and legitimacy, and leaves international law vulnerable to politicization rather than serving as a neutral framework for accountability. Unless international law develops a shared baseline capable of constraining both state and non-state violence, these distortions are likely to deepen as warfare continues to evolve.

1. “Greater leeway” refers here to specific legal recognition and protections afforded to certain NLMs. Shaw explains that Additional Protocol I recognizes qualifying national-liberation struggles as international armed conflicts and provides prisoner-of-war protections for qualifying combatants. ↩︎

Edited by Matteo de Campos Mello Grijns & Margaux Zani

The opinions expressed in this article are solely those of the author and they do not reflect the position of the McGill Journal of Political Science or the Political Science Students’ Association.

Featured image by Devonyu, obtained through iStock Photo