Indonesia Haze Crisis: Can Malaysia and Singapore Hold Indonesia Responsible Under International Law?
Introduction
The Indonesia haze crisis affecting Malaysia and Singapore in October 2026 has renewed questions about international responsibility for pollution crossing national borders. On October 9, Malaysian authorities closed schools in several states and federal territories, while 37 air-quality monitoring locations recorded unhealthy pollution levels. Singapore also experienced prolonged haze ahead of its Formula One Grand Prix (Reuters, 2026; Kok and Nair, 2026). Both countries can demand compliance with Indonesia’s international environmental obligations, but the movement of smoke across their borders does not automatically establish an internationally wrongful act or an entitlement to compensation.
The dispute has roots in the severe forest fires of 1997–1998, which prompted ASEAN governments to negotiate the Agreement on Transboundary Haze Pollution, adopted in 2002. Indonesia deposited its instrument of ratification on January 20, 2015, and became bound by the agreement later that year. Articles 4, 7, and 9 establish obligations concerning cooperation, environmental monitoring, fire control, and preventive measures, while Article 3 sets out principles guiding their implementation (ASEAN, 2002). These commitments provide Malaysia and Singapore with a legal basis for seeking action against transboundary pollution originating in Indonesia.
The agreement operates alongside the general international-law obligation to exercise due diligence in preventing significant environmental harm to other states. Yet identifying the geographical origin of the haze is insufficient to establish Indonesia’s responsibility. Forest and peatland fires may involve private land-management activities, while prolonged drought can complicate prevention and control. Under the rules of state responsibility, an internationally wrongful act requires conduct attributable to the state that breaches an applicable international obligation. Failures by Indonesian authorities to implement legally required preventive or regulatory measures could satisfy those conditions, depending on the evidence (ILC, 2001).
The possibility of enforcing these obligations presents a separate legal difficulty. Article 27 of the ASEAN agreement provides for consultation and negotiation but does not establish compulsory jurisdiction for an international court or arbitral tribunal. Malaysia and Singapore may assert claims concerning alleged treaty violations, although a binding judicial determination requires an independent basis of jurisdiction or the necessary state consent. Singapore’s Transboundary Haze Pollution Act 2014 provides a distinct domestic mechanism for pursuing criminal proceedings or civil claims against certain entities whose activities cause or contribute to haze pollution within Singapore.
Malaysia’s diplomatic engagement with Indonesia during the October emergency also illustrates the continuing importance of regional cooperation. Requests for information, offers of assistance, and coordinated firefighting measures can address immediate environmental risks without resolving questions of international responsibility. Any subsequent claim for reparation would require a separate assessment of the alleged breach, the resulting injury, and the necessary causal connection. The legal position ultimately depends on what Indonesia was obliged to do, whether its authorities fulfilled those obligations, and which remedies international law makes available to the affected states.
1. The October 2026 Haze Crisis in Malaysia and Singapore
The October 2026 haze crisis has disrupted public life across Malaysia and Singapore, as smoke from Indonesian forest and land fires continues to affect regional air quality. On October 8, Malaysian Education Minister Fadhlina Sidek announced that schools in Johor, Melaka, Negeri Sembilan, Selangor, Kuala Lumpur, Putrajaya, and the Rompin district of Pahang would close the following day. On October 9, government monitoring recorded unhealthy air quality at 37 locations, prompting precautionary measures to protect students and other vulnerable groups (Reuters, 2026c).
Malaysia measures atmospheric pollution using its Air Pollutant Index (API), which classifies readings of 101–200 as unhealthy, 201–300 as very unhealthy, and readings above 300 as hazardous. The distinction is relevant to assessing the severity of the emergency. The 37 monitoring locations reported on October 9 were classified as unhealthy; that figure does not establish that those locations experienced hazardous conditions.
Singapore faced similar concerns ahead of its Formula One Grand Prix. On October 8, the Meteorological Service Singapore recorded 24-hour Pollutant Standards Index (PSI) readings ranging from 98 to 139, covering moderate and unhealthy conditions. The Fédération Internationale de l'Automobile indicated that worsening pollution could require restrictions on entertainment and other outdoor activities, although the race itself was expected to proceed. Singapore's tourism authorities also prepared arrangements for medical assistance and N95 masks if needed (Kok and Nair, 2026).
The Malaysian API and Singaporean PSI are separate national measurement systems. Although both classify readings above 100 and up to 200 as unhealthy, their measurements should not be treated as identical evidence of individual exposure. Singapore additionally publishes one-hour PM2.5 concentrations to guide immediate outdoor activities. Health risks depend on pollution levels, exposure duration, and individual vulnerability, particularly among children, older adults, and people with respiratory or cardiovascular conditions.
Meteorological observations identify Indonesian territory as a major source of the smoke affecting Singapore. On October 8, Singapore's meteorological authorities reported moderate to dense smoke plumes moving from southern and central Sumatra and West Kalimantan toward the island. Prevailing southeasterly and southerly winds were expected to continue carrying pollution across the region, although extensive cloud cover limited the complete identification of fires and smoke plumes (MSS, 2026).
Peatland conditions contribute to the persistence of Indonesian fires. Drainage lowers groundwater levels and exposes organic peat deposits to drying, allowing combustion to continue beneath the surface after visible flames diminish. Agricultural land clearing and degraded land management can increase ignition risks, while the exceptionally dry conditions associated with the 2026 El Niño episode have made fire control more difficult. Reuters reported on October 5 that Indonesian authorities had recorded a substantial decline in satellite-detected hotspots, but environmental organizations warned that underground peat fires could remain active (Reuters, 2026a).
Satellite observations, wind measurements, and atmospheric dispersion models can help establish where smoke originates and how it crosses international borders. They do not, without additional evidence, identify every responsible land operator or demonstrate that Indonesian authorities breached their legal obligations. The physical origin of the haze is consequently an important starting point, but international responsibility depends on the conduct required of the state and the adequacy of its response.
2. Indonesia’s Obligations Under the ASEAN Haze Agreement
The ASEAN Agreement on Transboundary Haze Pollution was adopted in Kuala Lumpur on June 10, 2002, following the severe Southeast Asian forest fires of 1997–1998. Those fires demonstrated the regional consequences of land and forest burning, particularly when atmospheric conditions carried smoke across national boundaries. The agreement entered into force on November 25, 2003, establishing a binding framework for preventing, monitoring, and mitigating transboundary haze through national measures and regional cooperation (ASEAN, 2002).
Indonesia joined the treaty regime substantially later. Its parliament approved ratification through Law No. 26 of 2014, and the government deposited its instrument of ratification with the ASEAN Secretary-General on January 20, 2015. Under Article 29(2), the agreement entered into force for Indonesia on the sixtieth day following that deposit. Indonesia was consequently bound by its provisions during the October 2026 crisis.
The treaty establishes obligations of differing scope and precision. Some provisions require identifiable administrative measures, including monitoring and timely responses to fires. Others articulate principles governing environmental cooperation and the management of national resources. The applicable standard cannot be determined simply by observing that haze has crossed a border. It depends on the wording of the relevant obligation and the measures undertaken by the state concerned.
2.1 Prevention, Monitoring, and Immediate Fire Control
Article 3 recognizes the relationship between territorial sovereignty and environmental responsibility. States retain the sovereign right to exploit their natural resources, but they also bear responsibility for preventing activities within their jurisdiction or control from damaging the environment and human health of other states. The provision addresses cooperation, precaution, and sustainable resource management. Its opening language establishes principles that guide implementation, although the individual paragraphs use different normative formulations (ASEAN, 2002).
The agreement becomes more specific in Article 4. Parties must cooperate in developing and implementing measures to prevent and monitor transboundary haze, control fire sources, establish early warning systems, exchange information and technology, and provide mutual assistance. Article 4(3) additionally requires legislative, administrative, or other measures to implement the agreement. Compliance thus involves the actions of domestic authorities as well as participation in regional arrangements.
Article 7 imposes monitoring obligations covering fire-prone areas, existing land and forest fires, environmental conditions conducive to combustion, and haze arising from those fires. Parties must designate national monitoring centers to carry out these functions. Article 7(3) further requires immediate action to control or extinguish fires when they occur. This provision establishes a concrete duty of response, although successful suppression of every fire is not guaranteed.
Preventive measures are addressed in Article 9. They include the development of regulatory programs promoting zero-burning policies, monitoring vulnerable areas, strengthening local firefighting capabilities, encouraging community participation, and controlling land clearing through fire. These obligations are directly relevant to the management of plantation concessions and degraded peatlands, where recurring combustion risks require advance preparation.
Indonesia's compliance would depend on how those commitments were implemented under the circumstances of the 2026 fire season. The presence of legislation or an established monitoring agency would be relevant, but its existence alone would not settle whether the measures taken were appropriate. Effective implementation requires consideration of inspections, enforcement, warnings, operational preparedness, and the response to fires once detected.
2.2 Consultation, Information Sharing, and Assistance
Article 4(2) addresses the position of states affected by haze originating in another party's territory. The state from whose territory the pollution originates must respond promptly to relevant requests for information or consultations made by another affected or potentially affected state. Malaysia and Singapore can rely on this obligation when requesting information concerning Indonesian fire locations, preventive measures, and the authorities' response.
Article 8 provides for the communication of information obtained through national monitoring arrangements and its assessment within the regional system. Articles 10 and 11 concern preparedness and emergency response, including strategies, operational procedures, and the resources needed to address fires. These provisions recognize that effective control requires planning before an environmental emergency develops.
Emergency assistance is governed primarily by Article 12. A party requiring assistance may request it directly from another state or through the ASEAN coordinating arrangements. Assistance offered by another party may be employed only with the receiving state's consent. Article 13 further provides for the direction and control of assistance operations, preserving the receiving state's authority within its territory unless the parties agree otherwise (ASEAN, 2002).
Malaysia's willingness to support Indonesian firefighting efforts is consistent with these mechanisms. The agreement permits assistance involving technical expertise, equipment, personnel, and other resources, but it does not authorize foreign officials to conduct operations on Indonesian territory without the necessary consent. Regional cooperation remains legally structured around both mutual assistance and territorial sovereignty.
3. Transboundary Air Pollution and the No-Harm Principle
Indonesia's treaty obligations operate alongside the general international legal duty to exercise due diligence in preventing significant transboundary environmental harm. This duty concerns activities within a state's jurisdiction or control that present foreseeable risks to other states. It requires appropriate preventive conduct rather than guaranteeing that all cross-border environmental effects will be eliminated.
The relationship between sovereignty and environmental protection appears in Principle 21 of the 1972 Stockholm Declaration and Principle 2 of the 1992 Rio Declaration. Both affirm national authority over natural resources while recognizing responsibilities concerning environmental harm beyond national boundaries. The declarations are not themselves binding treaties, although their formulations have contributed to the articulation of general international environmental principles.
The International Court of Justice recognized the general obligation to respect the environment of other states and areas beyond national control in its advisory opinion on the Legality of the Threat or Use of Nuclear Weapons (ICJ, 1996, para. 29). In the context of Indonesian forest fires, this obligation directs attention toward the foreseeability of transboundary harm and the preventive measures reasonably required of national authorities.
The Trail Smelter arbitration provides an important historical example involving atmospheric pollution. The dispute arose from sulfur emissions produced by a smelter in British Columbia that caused damage in Washington State. Canada and the United States established an arbitral tribunal under a 1935 convention to resolve questions concerning compensation, future injury, and the operation of the facility.
The tribunal's 1938 award assessed compensation for damage occurring during the relevant earlier period and established temporary arrangements for controlling emissions. Its 1941 award addressed future transboundary injury and the permanent operational regime. The tribunal recognized Canada's international responsibility in the circumstances of the dispute and required measures intended to prevent further compensable harm.
The arbitration demonstrated that activities conducted within one state may engage international responsibility when they cause legally established injury abroad. Its conclusions, however, arose within a specific treaty-based arbitral process and the evidence presented concerning the smelter. The awards did not establish a universal rule of strict liability for every instance of atmospheric pollution or create compulsory jurisdiction over subsequent environmental disputes.
The International Court of Justice considered related questions in Pulp Mills on the River Uruguay (Argentina v. Uruguay). The case concerned the authorization of industrial facilities and obligations under the bilateral Statute of the River Uruguay of 1975. In its 2010 judgment, the Court found that Uruguay had breached procedural obligations concerning notification and cooperation but had not violated the substantive environmental obligations alleged by Argentina (ICJ, 2010).
The Court also addressed environmental impact assessment in circumstances involving a risk of significant transboundary harm. Its reasoning supports the importance of prior assessment and due diligence, but the procedural requirements arising under the bilateral river treaty cannot simply be transferred to unrelated activities. The applicable obligation must be identified in its own legal setting.
For the ASEAN haze dispute, the distinction between procedural and substantive duties is particularly relevant. A failure to respond to a legitimate request for information under Article 4(2) may raise a separate compliance question from the adequacy of measures taken to prevent or extinguish fires. Each obligation must be assessed according to its content and the conduct required for its performance.
4. Can Indonesia Be Held Responsible for the 2026 Fires?
International responsibility arises when conduct attributable to a state breaches an international obligation binding upon it. The International Law Commission's Articles on Responsibility of States for Internationally Wrongful Acts provide the principal analytical framework. Articles 1 and 2 identify the elements of an internationally wrongful act, while subsequent provisions address attribution, the consequences of breach, and the invocation of responsibility (ILC, 2001).
The ILC Articles are not an independent treaty. They were adopted by the Commission in 2001 and annexed to a United Nations General Assembly resolution. Many of their provisions reflect customary international law, although the status of particular rules must be assessed in the relevant legal context.
For Indonesia, the initial legal question concerns the obligations governing fire prevention, environmental monitoring, administrative implementation, and cooperation. A state may breach a duty requiring specific conduct even where compensable injury has not been established. Claims for financial reparation raise additional questions concerning damages and causation.
The factual inquiry would require examination of governmental decisions, enforcement practices, early warnings, and operational responses. The occurrence of extensive fires establishes the seriousness of the environmental situation, but the legal assessment depends on what Indonesian authorities were required to do and whether they fulfilled those duties.
4.1 Private Plantation Fires and State Attribution
Forest and land fires may involve private plantation operators, agricultural concession holders, contractors, and individual land users. Their commercial activities are not ordinarily attributable to Indonesia merely because they occur within Indonesian territory. International law distinguishes private conduct from actions or omissions legally attributable to state authorities.
Article 4 of the ILC Articles attributes the conduct of state organs to the state, including the conduct of governmental and administrative authorities. Article 8 addresses private conduct undertaken under the instructions, direction, or control of a state. An agricultural concession does not, without additional circumstances, establish that every action of the concession holder constitutes state conduct (ILC, 2001).
Governmental omissions may nevertheless provide an independent basis for international responsibility. Authorities could breach applicable obligations by failing to adopt necessary preventive measures, inadequately enforcing regulations, or delaying a response that the treaty requires. In such circumstances, attribution concerns the conduct of public officials or institutions rather than the private burning itself.
The distinction is particularly relevant where land-use regulation involves multiple levels of government. Information concerning concession permits, inspections, sanctions, and firefighting responsibilities could establish which authorities had relevant powers and what measures they undertook. The nationality of a company's shareholders would not, by itself, determine the international responsibility of Indonesia or another state.
4.2 Due Diligence, El Niño, and Evidence of Breach
Due diligence is assessed in relation to the applicable obligation, the risks involved, and the measures reasonably available to the state. Recurring fires can make environmental damage more foreseeable, especially in areas with extensive peat deposits and established histories of burning. Prior warnings, monitoring records, restrictions on open burning, and available firefighting resources are relevant to evaluating the adequacy of governmental conduct.
The existence of national prevention programs is evidence of regulatory activity, but implementation remains essential. Authorities may enact restrictions without enforcing them effectively, while substantial preventive measures may still prove insufficient during unusually severe conditions. The inquiry concerns whether the state adopted and implemented the measures required by the applicable legal standard, taking account of the circumstances confronting it.
The 2026 El Niño episode is relevant because exceptionally dry conditions can increase ignition risks and complicate suppression. Underground peat combustion may continue despite operations that reduce visible surface fires. Weather conditions could affect the assessment of what was reasonably achievable, but they do not eliminate duties concerning preparation, monitoring, or appropriate emergency response.
Article 23 of the ILC Articles recognizes force majeure only under restrictive conditions. The event must involve an irresistible force or unforeseen occurrence beyond the state's control that makes performance of the obligation materially impossible. The provision also contains limitations concerning situations to which the invoking state contributed. Severe drought, operational difficulty, or increased firefighting costs would not automatically meet that standard (ILC, 2001).
Evidence concerning the timing and effectiveness of Indonesia's response would be particularly significant. Satellite hotspot figures may indicate changes in detected fire activity, but they cannot establish whether all fires were extinguished or whether preventive duties were fulfilled. The assessment requires examining administrative and operational conduct against the obligations applicable during the emergency.
4.3 The West Kalimantan Lawsuit Against Indonesian Authorities
The regional haze emergency has coincided with domestic litigation over the management of Indonesian fires. In September 2026, Indigenous representatives and civil society organizations in West Kalimantan brought a class action against public authorities, alleging serious failures to prevent and respond to recurring forest and land fires. President Prabowo Subianto and the governor of West Kalimantan were among the ten defendants identified in contemporary reporting (Holmes, 2026).
The plaintiffs seek measures concerning environmental rehabilitation, recovery, and health-related costs. Their allegations concern governmental responsibility for recurring pollution and the adequacy of preventive action. These remain claims advanced by the litigants rather than findings of unlawful conduct.
The initial hearing took place in Pontianak on October 7. Representatives of the central government did not attend, prompting criticism from the plaintiffs. Representatives of local governments named as co-defendants were present and submitted documents to the presiding judge. The hearing was adjourned until October 21, and the proceedings had not produced a judgment on the merits as of October 9 (Reuters, 2026b).
Domestic litigation may generate evidence relevant to an international assessment, including records concerning official warnings, enforcement decisions, and environmental management. Its legal conclusions, however, would depend on the Indonesian law applied by the court. Even a subsequent domestic finding of governmental negligence would require separate examination before it could support a claim that Indonesia breached an international obligation owed to Malaysia or Singapore.
5. Can Malaysia and Singapore Take Indonesia to Court?
Malaysia and Singapore may assert claims concerning Indonesia's compliance with international environmental obligations. Where the conditions for invoking state responsibility are satisfied, an injured state may seek cessation of wrongful conduct, appropriate assurances of non-repetition, or reparation for injury caused by the breach. The right to assert such claims is distinct from the jurisdiction of any particular international tribunal.
Article 42 of the ILC Articles identifies the circumstances in which a state may invoke responsibility as an injured state. Its application depends on the obligation allegedly breached and the legal position of the state seeking to invoke responsibility. Article 43 addresses notification of the claim to the responsible state, including the conduct that the claimant considers necessary to bring the breach to an end (ILC, 2001).
Malaysia and Singapore would need to identify the relevant obligation, establish the alleged breach, and demonstrate the legal basis on which they invoke responsibility. Their exposure to transboundary pollution is important, but injury under the applicable rules cannot be assumed without examining the nature and scope of the obligation concerned.
Judicial proceedings present a separate jurisdictional issue. International courts and tribunals act according to their founding instruments and the jurisdictional commitments of the states concerned. The existence of an arguable international claim does not independently authorize compulsory adjudication.
5.1 Article 27 and the Limits of ASEAN Dispute Settlement
Article 27 of the ASEAN Agreement on Transboundary Haze Pollution governs disputes concerning its interpretation, application, or compliance. It requires such disputes to be settled amicably through consultation or negotiation. The provision does not establish compulsory arbitration or confer jurisdiction on the International Court of Justice (ASEAN, 2002).
Malaysia and Singapore could pursue consultations concerning Indonesia's preventive measures, environmental monitoring, fire suppression, or responses to requests for information. Negotiations could also address alleged violations and possible remedies. The treaty provides a legal setting for these discussions without predetermining their outcome.
The absence of compulsory adjudication affects the practical enforcement of the agreement. A state may remain subject to a binding obligation even where another party cannot obtain a judicial determination without additional consent. Article 27 does not establish an international compensation tribunal, automatic financial penalties, or a procedure through which one state may unilaterally impose a binding judgment on another.
Diplomatic consultations may nonetheless produce concrete results. States can agree on operational assistance, improved monitoring, information exchange, or measures intended to prevent recurrence. Any settlement must be distinguished from a judicial finding of responsibility, particularly where the parties resolve immediate difficulties without deciding whether a past violation occurred.
5.2 Jurisdiction of the International Court of Justice
The International Court of Justice may decide contentious disputes only where the necessary basis of jurisdiction exists. Article 36 of its Statute recognizes several possible foundations, including special agreements between states, jurisdictional clauses in treaties, and declarations accepting compulsory jurisdiction under Article 36(2).
Under the optional-clause system established by Article 36(2), jurisdiction depends on the relevant declarations and their applicable conditions. As of October 2026, the United Nations Treaty Collection does not list operative declarations by Indonesia, Malaysia, or Singapore accepting compulsory jurisdiction under that provision. Their participation in the United Nations does not itself supply the missing consent.
Nor does Article 27 of the ASEAN haze agreement confer jurisdiction on the Court. Its dispute-settlement provision directs the parties toward consultation and negotiation. Ratification of that agreement cannot be treated as acceptance of compulsory ICJ jurisdiction.
The states could nevertheless submit a particular dispute through a special agreement. Another independently applicable jurisdictional instrument could also provide a basis if its terms and conditions were satisfied. Such possibilities must be distinguished from the jurisdictional arrangements currently established for the haze dispute.
Environmental harm, however serious, does not remove these requirements. The Court's competence to decide a claim must be established independently of the evidence concerning the alleged treaty violation or the scale of its consequences.
5.3 International Arbitration by State Consent
International arbitration could provide an alternative means of determining alleged violations of environmental obligations. Indonesia and an affected state could agree to submit specified questions to an arbitral tribunal, including questions concerning preventive duties, governmental conduct, or reparation.
An arbitration agreement would define the tribunal's jurisdiction, the matters submitted, the applicable law, and the procedures governing the case. It could also regulate the binding effect and implementation of the award. These matters would depend on the terms accepted by the participating states.
The Trail Smelter arbitration illustrates this consensual model. Canada and the United States established a tribunal under their 1935 convention, allowing the arbitrators to determine questions concerning cross-border atmospheric pollution. The awards demonstrate the possibility of adjudicating environmental claims through arbitration, but they create no jurisdiction over Indonesia.
For the October 2026 crisis, arbitration remains dependent on the necessary state consent. The ASEAN agreement does not authorize Malaysia or Singapore to compel Indonesia to participate in arbitration solely because consultations have failed.
6. Compensation and Other Forms of International Reparation
Where an internationally wrongful act is established, the responsible state may be required to cease continuing unlawful conduct and provide appropriate assurances or guarantees of non-repetition. Article 30 of the ILC Articles addresses these consequences, while Article 31 establishes the principle of full reparation for injury caused by an internationally wrongful act (ILC, 2001).
Reparation may take the form of restitution, compensation, or satisfaction under Articles 34–37. Restitution seeks to restore the situation that existed before the wrongful act, subject to the relevant legal limitations. Compensation addresses financially assessable damage not made good by restitution. Satisfaction may remedy injury that cannot adequately be addressed through those other forms.
For Malaysia and Singapore, potentially relevant losses could include public expenditure associated with health protection, damage to property, and demonstrable commercial losses caused by the haze. Disruption to education, tourism, or outdoor activities may provide evidence of consequences requiring assessment. Such disruption, however, is not itself a determination of the amount legally recoverable from Indonesia.
International law recognizes that environmental injury may be compensable independently of conventional property damage. In Certain Activities Carried Out by Nicaragua in the Border Area (Costa Rica v. Nicaragua), the International Court of Justice addressed compensation after finding Nicaragua responsible for unlawful activities on Costa Rican territory. Its 2018 judgment recognized compensation for environmental damage, including the impairment or loss of ecosystem goods and services and appropriate restoration costs (ICJ, 2018).
The Court considered the existence and extent of environmental injury, whether it resulted directly and certainly from the wrongful activities, and the appropriate method of valuation. It did not adopt a universally prescribed valuation formula. Its assessment reflected the circumstances and evidence concerning the affected wetland.
The judgment provides a relevant approach to proving environmental damage, but the Indonesian haze crisis involves different factual circumstances. Smoke may originate from numerous fires across separate locations, while pollution exposure and resulting harm may vary across communities. A compensation claim would require evidence connecting particular losses to the conduct constituting the alleged international breach.
This distinction is especially significant where the alleged wrongful conduct consists of inadequate prevention or regulatory enforcement. Demonstrating that haze caused economic disruption would not necessarily establish that the same loss resulted from a legally attributable omission. The claimant would need to address the relevant counterfactual question: what harm would reasonably have been avoided had Indonesia fulfilled the obligation allegedly breached?
States may also negotiate remedial commitments without obtaining an international judgment. Agreements concerning improved monitoring, restoration, fire control, or financial arrangements could contribute to resolving a dispute. Their legal character would depend on what the parties agreed, rather than on an assumption that every cooperative measure constitutes reparation for an established wrongful act.
7. Singapore’s Transboundary Haze Pollution Act 2014
Singapore's Transboundary Haze Pollution Act 2014 provides a domestic mechanism for addressing certain activities that cause or contribute to haze pollution within its territory. Section 4 establishes the Act's extraterritorial application, allowing relevant conduct outside Singapore to fall within its scope. The legislation applies to specified entities and forms of conduct, rather than imposing international responsibility on Indonesia as a state (Singapore, 2014).
The Act is particularly relevant to agricultural and plantation operations conducted abroad. Its provisions address entities that own or occupy land and certain entities participating in the management of other entities operating on foreign land. Responsibility under the statute depends on the conditions set out in its individual provisions, including the entity's conduct and its relationship to the pollution affecting Singapore.
The legislation and the ASEAN agreement operate through different legal systems. The ASEAN treaty establishes obligations between states, while Singapore's statute provides domestic criminal and civil mechanisms concerning qualifying entities. Liability under one regime does not establish liability under the other, even when both arise from the same fires.
7.1 Criminal and Civil Liability of Companies
Section 5 of the Act establishes offenses involving conduct that causes or contributes to haze pollution in Singapore. It also addresses conduct by an entity that condones relevant activities of another entity or individual, as well as specified circumstances involving participation in the management of a landowner or occupier outside Singapore.
An entity convicted under Section 5 may be fined up to S$100,000 for each day or part of a day during which the relevant haze pollution occurs. Additional fines of up to S$50,000 per day may apply where the statutory conditions concerning failure to comply with a preventive measures notice are established. Section 5(5) imposes a maximum aggregate fine of S$2 million for the relevant conviction (Singapore, 2014, s. 5).
Civil liability is governed by Section 6. The provision establishes duties concerning conduct that causes, contributes to, or condones haze pollution in Singapore, including specified management relationships involving entities operating abroad. A breach may support an action for breach of statutory duty where a person in Singapore suffers qualifying injury in consequence of that breach.
The categories of injury include personal injury, disease, mental or physical incapacity, physical property damage, and economic loss, including lost profits. Civil recovery remains subject to Section 7 and the defenses and other legal incidents applicable to actions for breach of statutory duty. The statute thus provides a potential remedy for qualifying losses without requiring a separate international determination of Indonesia's responsibility.
Neither the statutory penalties nor the civil provisions establish liability for any particular company involved in the October 2026 fires. A criminal prosecution or civil claim would have to satisfy the applicable legal requirements, including the statutory definition of haze pollution and the rules governing proof.
7.2 Evidence, Statutory Defenses, and Enforcement Abroad
The Act contains specific provisions addressing the evidentiary difficulties of transboundary pollution. Section 8 establishes rebuttable presumptions concerning the relationship between fires abroad and haze in Singapore. Where the statutory conditions are satisfied, satellite information, wind direction, wind velocity, and other meteorological evidence may support a presumption that smoke from an identified fire contributed to the pollution.
Other presumptions concern ownership or occupation of foreign land and specified relationships between entities. Maps obtained from foreign governments, relevant authorities, or other prescribed sources may have evidentiary significance. These provisions assist in establishing facts that would otherwise be difficult to prove when the suspected source is located beyond Singapore's territory.
The definition of a poor air-quality episode is especially important. The Transboundary Haze Pollution (Air Quality) Regulations 2014 prescribe a threshold of 101 for the purposes of Section 2(2). The relevant index is the 24-hour PSI adopted by Singapore's National Environment Agency for fine particulate matter measuring 2.5 micrometers or less in aerodynamic diameter. The Act also requires satisfaction of its conditions concerning the continuation of the qualifying pollution episode over the following 24-hour period (National Environment Agency, 2014).
These statutory conditions must be distinguished from ordinary public descriptions of unhealthy air quality. A reported PSI reading above 100 at a particular time does not, by itself, establish that the full legal definition has been satisfied. Nor do meteorological observations automatically identify which entity engaged in conduct covered by Sections 5 or 6.
Section 7 establishes defenses under specified conditions. An accused entity or civil defendant may rely on the defense that the haze pollution was caused solely by a qualifying grave natural disaster or phenomenon, or by an act of war, subject to the statutory requirements. Other defenses address conduct by third parties without the relevant entity's knowledge or consent, conduct contrary to its instructions, and reasonable preventive or remedial measures in particular circumstances.
Those defenses do not apply uniformly to every offense or civil claim. The third-party defenses are limited to specified categories of conduct and exclude reliance on certain employees, agents, contractors, and persons connected with relevant land-use arrangements. The statutory limitations are important because an entity cannot necessarily avoid responsibility by identifying another person as the immediate actor.
Enforcement presents practical difficulties when companies, witnesses, records, and relevant land are located abroad. Investigations may require access to concession maps, corporate information, and evidence concerning specific fires. Service of legal documents, prosecution, and enforcement of judgments or penalties raise distinct procedural questions. Singapore's extraterritorial legislation does not give its authorities unrestricted enforcement powers within Indonesian territory.
The Act provides a means of pursuing accountability for specified commercial conduct, but its effectiveness depends on evidence, jurisdiction, and the available enforcement mechanisms. Corporate liability under Singaporean law remains separate from the responsibility of Indonesia under the ASEAN agreement and general international law.
8. ASEAN Diplomacy and the Limits of Regional Enforcement
Malaysia's response to the October 2026 haze emergency has emphasized diplomatic engagement and regional coordination. On October 8, Prime Minister Anwar Ibrahim stated that Indonesian President Prabowo Subianto had agreed to take necessary measures to address the haze. Anwar also expressed Malaysia's willingness to assist Indonesia and requested efforts to arrange an ASEAN ministerial meeting on the regional response (Reuters, 2026c).
These exchanges concern cooperation during an ongoing environmental emergency. They do not establish that Malaysia formally invoked Article 27 of the ASEAN agreement or that Indonesia admitted an international legal violation. Diplomatic discussions may address compliance and assistance without resolving responsibility for earlier conduct.
ASEAN possesses several mechanisms relevant to transboundary haze. The ASEAN Specialised Meteorological Centre provides regional information concerning fire hotspots, smoke plumes, atmospheric conditions, and seasonal risks. Its monitoring supports national early warning systems and the identification of pollution moving between states. During the 2026 fire season, such information was particularly relevant to assessing conditions in Sumatra and Kalimantan.
The ASEAN agreement also establishes a Conference of the Parties responsible for reviewing implementation and undertaking functions within the treaty's mandate. Article 5 envisages the ASEAN Coordinating Centre for Transboundary Haze Pollution Control, intended to facilitate regional cooperation in managing fires and resulting pollution. National authorities retain primary responsibility for firefighting and domestic emergency operations.
Institutional development advanced in April 2026 when Indonesia inaugurated the coordinating center's secretariat in Jakarta. The Indonesian Ministry of Environment described the inauguration as an important step toward strengthening regional environmental cooperation. The physical establishment of the secretariat, however, must be distinguished from the completion of all legal requirements governing the center's operation.
At its June 25, 2026 meeting, ASEAN's Sub-Regional Ministerial Steering Committee on Transboundary Haze Pollution in the Mekong Sub-Region continued to anticipate the deposit of ratification instruments necessary for the entry into force of the center's separate establishment agreement. The committee linked those steps to the center's full operationalization in Indonesia (ASEAN, 2026). The inauguration of the secretariat did not, by itself, establish that this process had been completed.
Regional policy coordination also operates through the Second ASEAN Haze-Free Roadmap 2023–2030, adopted at the eighteenth Conference of the Parties on August 23, 2023. The roadmap establishes updated objectives, strategies, indicators, and implementation arrangements directed toward a transboundary haze-free ASEAN by 2030. It addresses sustainable land management, peatland protection, fire prevention, institutional cooperation, and the mobilization of relevant resources (ASEAN, 2024).
The roadmap supports implementation of the binding treaty but is not an independent convention establishing compulsory judicial jurisdiction or compensation procedures. Its objectives may provide benchmarks for assessing regional progress and identifying implementation shortcomings. Failure to achieve a policy target does not, without further legal analysis, establish that a particular state breached an international obligation.
ASEAN's arrangements reflect a system in which regional monitoring and cooperation coexist with substantial dependence on domestic regulatory action. Institutions can share information, coordinate technical support, and facilitate assistance. They cannot independently replace national authorities in inspecting concessions, enforcing land-use restrictions, or directing all firefighting operations within a state's territory.
The recurrence of severe haze demonstrates the continuing difficulty of translating regional commitments into effective prevention. Stronger coordination may improve responses, but the central legal inquiry remains tied to Indonesia's obligations and conduct. Diplomatic cooperation can address the immediate emergency while leaving open the possibility of a subsequent legal claim if the necessary elements of international responsibility are established.
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Conclusion
Malaysia and Singapore can demand compliance with Indonesia's obligations under the ASEAN Agreement on Transboundary Haze Pollution. The treaty establishes binding commitments concerning prevention, monitoring, fire control, information sharing, and cooperation. General international environmental law also requires appropriate diligence in addressing foreseeable risks of significant transboundary harm. These obligations apply even though international law does not guarantee the complete elimination of smoke crossing national borders.
Establishing responsibility for the October 2026 crisis would require identifying an applicable obligation and demonstrating that conduct attributable to Indonesian authorities breached it. A claim for compensation would additionally require proof of injury sufficiently connected to the wrongful act. Although the ASEAN agreement provides for consultations and negotiations, it does not establish compulsory judicial or arbitral jurisdiction. Proceedings before an international tribunal would depend on another valid jurisdictional basis or the necessary consent of the states concerned.
Singapore's Transboundary Haze Pollution Act offers a separate means of pursuing qualifying entities whose activities cause or contribute to haze within its territory.
ASEAN institutions provide mechanisms for monitoring and cooperation, while effective prevention continues to depend substantially on national implementation. Indonesia's existing international obligations are legally binding; whether their breach can be established in relation to the 2026 fires remains a question of evidence, applicable legal standards, and the procedures available to the affected states.
References
ASEAN Agreement on Transboundary Haze Pollution (2002) Adopted in Kuala Lumpur on 10 June 2002; entered into force on 25 November 2003. Available at: https://www.asean.org/wp-content/uploads/2021/01/ASEANAgreementonTransboundaryHazePollution-1.pdf (Accessed: 9 October 2026).
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