From a leaked phone call to airstrikes: What sparked the deadly Thailand–Cambodia border clashes
The clashes began on 24 July 2025, following months of escalating tensions and political friction
A five-day conflict erupted between Thailand and Cambodia in late July 2025, marking the most serious border fighting between the two neighbors in over a decade.
The clashes began on 24 July 2025, following months of escalating tensions and political friction. The fighting-marked by artillery exchanges and airstrikes-killed dozens, injured hundreds, and displaced more than 300,000 people on both sides of the border.
A ceasefire brokered on 28 July halted the worst of the violence, but tensions remain high, with both governments accusing each other of breaching the truce.
Keep updated, follow The Business Standard's Google news channel
Why it happened
The conflict is rooted in a web of historical grievances, territorial disputes, and political instability that has long haunted Thai–Cambodian relations.
1. Historical and territorial disputes
- Colonial-era boundaries: Much of the disagreement stems from the Franco–Siamese Treaties of 1904 and 1907, which set borders when France ruled Indochina. The demarcation remains disputed to this day.
- The Preah Vihear Temple: In 1962, the International Court of Justice (ICJ) ruled that the ancient Hindu temple belonged to Cambodia, but left the surrounding land undefined. Thailand has never accepted the ICJ's full jurisdiction, keeping the issue alive.
- Nationalism and resentment: Both sides have used border nationalism as a rallying cry. Cambodian commentators accuse Thailand of seeking to "reclaim" land lost in the 18th century, while Thai hardliners view the ICJ ruling as an affront to sovereignty.
2. Immediate triggers
- A deadly skirmish: A brief clash on 28 May 2025 in the Emerald Triangle killed a Cambodian soldier and reignited tensions.
- Landmine incident: On 23 July, a Thai soldier lost a leg after stepping on a PMN-2 landmine near the border. Thailand blamed Cambodia for laying new mines-potentially violating the Ottawa Treaty-which Cambodia denied, insisting the issue be taken to the ICJ.
-
![A member of the Thailand Mine Action Centre (TMAC) demonstrates a PMN-2 mine detonation during a media visit organized by the Royal Thai Army, following a ceasefire between Cambodia and Thailand, in Surin province, Thailand, August 20, 2025. Photo: REUTERS/Chalinee Thirasupa]()
A member of the Thailand Mine Action Centre (TMAC) demonstrates a PMN-2 mine detonation during a media visit organized by the Royal Thai Army, following a ceasefire between Cambodia and Thailand, in Surin province, Thailand, August 20, 2025. Photo: REUTERS/Chalinee Thirasupa
What made it worse
The local dispute quickly evolved into a national crisis, fed by domestic politics, economic retaliation, and military brinkmanship.
- Leaked phone call and Thai political turmoil:
A leaked June 18 conversation between Cambodia's Senate President Hun Sen and then–Thai Prime Minister Paetongtarn Shinawatra deepened the rift. In the recording, Paetongtarn allegedly called the Thai military her "opposition," triggering a political crisis that led to her removal from office in August. Hun Sen's involvement angered Bangkok and revived old rivalries between the Hun and Shinawatra dynasties. - Transnational crime crackdown:
Thailand launched a crackdown on cyber-scamming rings operating along the Cambodian border, reportedly generating up to US$19 billion annually. Tighter border controls disrupted trade and labor flows, stoking economic resentment in Cambodia. - Tit-for-tat retaliation:
Border closures followed, halting over US$10 billion in annual trade. Each side expelled the other's ambassador, and diplomatic relations plunged to their lowest point in years. - Full-scale fighting:
On 24 July, hostilities broke out.- Cambodian forces fired BM-21 rocket launchers, hitting civilian areas in Thailand-including a gas station and a hospital-killing at least eight.
- Thailand retaliated with F-16 airstrikes on Cambodian military targets.
- Acting Thai Prime Minister Phumtham Wechayachai warned the fighting could escalate into a "full-scale war."
How it ended
Despite deep mistrust, regional diplomacy and global pressure helped pull both sides back from the brink.
- Ceasefire brokered:
On 28 July, after mediation by Malaysia-then ASEAN chair-and diplomatic pressure from the United States and China, the two countries agreed to an unconditional ceasefire. - Fragile truce:
Sporadic clashes and landmine incidents continued in the following weeks, though both governments refrained from major offensives. The ICRC confirmed Thailand was treating captured Cambodian soldiers in line with humanitarian norms. - Structured negotiations:
- At the 7 August General Border Committee (GBC) meeting, both sides agreed to a 13-point plan, including halting hostilities, maintaining communication between local commanders, and deploying an ASEAN observer team.
- On 10 September, they met again, pledging to withdraw heavy weapons within three weeks, jointly clear mines, curb online scam operations, and reopen border trade.
- Continued diplomacy:
Talks in Shanghai, hosted by China, reaffirmed the ceasefire. In a symbolic gesture, Cambodian Prime Minister Hun Manet even nominated former US President Donald Trump for the Nobel Peace Prize for helping broker the truce.
Why it matters
The border crisis has tested ASEAN's capacity for regional conflict resolution and underscored how domestic politics, crime networks, and historical grievances can ignite modern conflicts in Southeast Asia.
Both economies have been hit hard-Cambodia by the return of nearly 800,000 migrant workers and disrupted supply chains, and Thailand by the cost of military mobilization and border insecurity.
While the guns have fallen silent, the root causes -territorial ambiguity, nationalism, and mistrust- remain unresolved, leaving the peace fragile and the frontier uneasy.
