Thailand and Cambodia in Water Resource Tensions Border Conflict and Mekong Dispute

Post by : Priya

  Photo:Reuters

A deepening conflict between Thailand and Cambodia over border lines and control of water resources in the Mekong basin has escalated into active armed clashes. Once a relatively minor dispute, it has transformed into the most serious confrontation between the two countries in over a decade. The clash has triggered fatalities, massive displacement, and raised concerns across Southeast Asia over water security, national sovereignty, and regional stability.

Historical Background

The roots of this dispute trace back to the Franco‑Siamese Treaty map of 1907, drawn during French colonial rule. That map delineated territory that remains contested today, especially around the sacred Preah Vihear temple complex. Subsequent rulings by the International Court of Justice (ICJ), first in 1962 and again in 2013, recognised Cambodia's sovereignty over Preah Vihear. Yet, competing national narratives and strong nationalist sentiments in both Thailand and Cambodia have kept tensions simmering 

In the broader Mekong context, water governance has long been a source of friction among riparian states. Countries such as Laos, Thailand, Cambodia, and Vietnam jointly share river resources, yet each pursues hydroelectric, irrigation, and economic development projects that often clash with environmental and social needs. While bodies like the Mekong River Commission exist to promote cooperation, they lack binding authority over national projects, leaving gaps in joint management 

Triggering the Current Crisis
On May 28, 2025, a Cambodian soldier was killed near the Preah Vihear‑area border. Both sides blamed each other for the incident. Soon after, a landmine explosion injured Thai soldiers, allegedly caused by Cambodian‑placed mines. This sequence ignited a rapid escalation into full military confrontation 

Between May 28 and late July 2025, exchanges of artillery, rockets, small arms fire, and air strikes resulted in substantial casualties and displacements. Thai sources reported air strikes using F‑16 jets and Cambodian rocket attacks, while Cambodia accused Thailand of aggressive incursion, including naval movements involving riverine vessels 

By July 24, armed conflict was open and intense: rockets fired by Cambodia, Thai artillery responses, and Thai F‑16 strikes topped the violence, taking the crisis to its most dangerous stage in over 10 years 

Human Cost and Displacement
As of late July 2025, more than 30 people have died and over 200,000 civilians have been forced to flee across both sides of the border. Official figures included more than 130,000 displaced in Thailand and over 100,000 in Cambodia 

Civilians report entire villages emptied, hospitals damaged, and camps filled with families receiving aid—water, food, shelter—amid uncertain futures. Reports describe daily life shattered at the border with chaos and fear setting in quickly 

The Water Resource Dimension
While much attention is on the border fighting, a deeper territorial dimension underlies the conflict: access to and control over Mekong water. Cambodia has moved forward with ambitious projects like the Funan Techo canal—intended to link the Mekong River to the Gulf of Thailand. Announced as a $1.7 billion initiative, the canal aims to boost exports, reduce reliance on Vietnamese ports, and enhance national prestige. Yet environmental experts warn of severe downstream impacts: disruption of natural flooding, nutrient distribution, fisheries collapse and exacerbated droughts in Vietnam and Thailand 

Plans for major dams such as the Sambor and Stung Treng on the Mekong mainstream have compounded worries. These dams could displace thousands, impede fish migration, significantly alter river ecology, and reduce sediment flows vital to floodplain agriculture 

For fishermen along the Tonlé Sap and throughout the Mekong delta, these hydrological changes are existential threats. Many families have already seen drastic declines in fish catches, forcing socioeconomic migration and deepening regional inequality 

Diplomatic Breakdown
Diplomacy between the two capitals has deteriorated sharply. A leaked phone call in June between the Thai prime minister and Cambodian leadership sparked domestic outrage in Thailand, with one Thai political ally withdrawing support from its coalition government 

Thailand has pushed for bilateral talks to de‑escalate the situation, refusing to involve third‑party legal bodies unless Cambodia stops the violence. Cambodia, in contrast, continues seeking legal arbitration, including potential new ICJ claims over areas still under dispute, such as Ta Moan Thom and Ta Kro Bei 

At the broader regional level, ASEAN pressure and UN Security Council discussions have urged immediate ceasefire and negotiations. Cambodian leaders have formally called for an urgent ceasefire as talks began in Malaysia on July 28, 2025, brokered by ASEAN with support from major powers. Thailand questioned Cambodia’s sincerity in stopping the violence during talks .

Analytical Viewpoints

Observers see several converging fault lines in this crisis:

• Legacies of colonial-era maps and unresolved sovereignty claims, especially around cultural heritage sites.
• Domestic nationalism, which inflames public sentiment on both sides and limits space for compromise.
• Strategic resource control—Cambodia’s infrastructure hints at ambitions for water control and economic leverage, while Thailand appears concerned about losing access and influence.

Weak multilateral governance of Mekong resources, as institutions like the Mekong River Commission lack enforcement power, and regional projects often bypass consultation protocols .

China’s rising influence, via funding and infrastructure—particularly the canal project supported by Chinese companies—which alarms neighbouring countries over both ecological impact and strategic coastal access .

Stakes for Water Security

Water conflict in the Mekong is more than local—it affects millions. In dry seasons, both Thailand and Cambodia draw heavily from the river and its tributaries. Lower water flow can cause agricultural losses in Vietnam’s delta, saltwater intrusion, food insecurity, and increased poverty in riparian communities .

Failure to coordinate upstream and downstream extraction, sediment trapping from dams, or strategic diversion via canals can result in cumulative ecological damage. This includes loss of fish stocks, degradation of floodplain soils, and threats to biodiversity, including endangered species like the Irrawaddy dolphin .

Humanitarian and Economic Fallout

The ongoing fighting has caused widespread suffering:

• Displacement of over 200,000 people.
• Interruptions to farming, supply chains, and cross-border trade.
• Emergency humanitarian support struggling to keep up in evacuation centres.
• Damage to infrastructure—roads, hospitals, and homes.
• Collapse of livelihoods in border communities and fishing villages.

At the same time, canal and dam projects promise long-term economic gain—but at great social and ecological cost. Without robust environmental assessments, local voices are sidelined while large firms and foreign financiers shape outcomes.

Potential Pathways Forward

To avoid a full-scale war and further regional destabilisation, the following steps appear essential:

• Immediate ceasefire and troop withdrawal. Both sides must honor de-escalation positions agreed in earlier 2024 talks and halt active hostilities during negotiations.
•  Multilateral negotiations beyond bilateral diplomacy. ASEAN and regional powers like the U.S., China, and Vietnam can play constructive roles in mediating talks that include water governance frameworks.
•  Binding water cooperation agreements. Mekong countries should strengthen the Mekong River Commission with legally enforceable protocols on dams, diversion, and canal projects to ensure river health for all.
•  Independent environmental and social impact assessments. Projects such as the Funan Techo canal and the Sambor/Stung Treng dams must be subjected to independent scrutiny, with transparency and public input.
• Cultural dialogue and confidence-building. Reconciling shared heritage and national pride could defuse nationalist tensions—beginning with joint preservation or development of temple sites as neutral grounds.
•  Humanitarian relief and protection. Civilians displaced by fighting deserve protection, rapid aid deployment, and clear plans for recovery and safe return.

Thailand Cambodia water dispute