Overview
A Cambodian soldier died in a border firefight on May 28. Within two months, the countries were exchanging artillery fire and airstrikes across a dozen locations. Three ceasefires later—brokered by Malaysia, pressured by Trump, witnessed by ASEAN—over 100 people are dead and a million displaced. The latest truce, signed December 27, holds the same promise as the ones before it.
The fight is over an 800-kilometer border that's been disputed since French colonial mapmakers drew lines that didn't match the terrain. The temple of Preah Vihear sits at the center—a thousand-year-old ruin the International Court of Justice awarded to Cambodia in 1962, leaving the surrounding land ambiguous enough to keep armies mobilized for decades.
Key Indicators
People Involved
Organizations Involved
Ten-nation bloc that's struggled to enforce peace between two of its members.
UN's highest court ruled on the temple in 1962 but left land disputes unresolved.
Timeline
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Third Ceasefire Takes Effect
DiplomaticDefense ministers sign agreement. Troop freeze, POW release in 72 hours if ceasefire holds, ASEAN monitors.
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Death Toll Reaches 96
Casualty ReportEighteen days of fighting. Nearly one million displaced on both sides.
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Emergency Talks Begin Despite Ongoing Clashes
DiplomaticDefense ministers meet while fighting continues. Cambodia accuses Thailand of bombarding villages.
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Fighting Resumes After Two-Month Truce
MilitaryBoth sides accuse each other of ceasefire violations. Clashes erupt along border.
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Kuala Lumpur Peace Accord Signed
DiplomaticComprehensive ceasefire at ASEAN Summit. Trump and Anwar witness. POW release provisions included.
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Anutin Elected Prime Minister
PoliticalParliament elects Anutin with 311 votes. Promises elections within four months.
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Paetongtarn Officially Removed
PoliticalConstitutional Court rules 6-3 to dismiss PM over Hun Sen phone call.
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ASEAN Observer Teams Established
DiplomaticBoth sides sign Terms of Reference for ASEAN monitoring team led by Malaysia's defense chief.
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First Ceasefire: Putrajaya Agreement
DiplomaticEmergency talks in Malaysia produce ceasefire after five days of fighting. ASEAN, US, China support.
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Trump Threatens Trade Consequences
DiplomaticUS President calls both leaders, threatens to withhold trade agreements unless fighting stops.
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Fighting Erupts Across 12 Border Locations
MilitaryGunfire, artillery, rockets exchanged. Thai airstrikes target Cambodian positions near Ta Muen Thom temple.
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Thai Patrol Hits Landmine
MilitaryFive soldiers injured in Ubon Ratchathani. Thailand accuses Cambodia of laying new mines, recalls ambassador.
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Thai PM Suspended by Court
PoliticalConstitutional Court suspends Paetongtarn over ethics violations in phone call.
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Hun Sen Leaks Recording
Political9-minute excerpt published. Paetongtarn heard calling military commander unhelpful, asking Hun Sen for sympathy.
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Paetongtarn's Phone Call With Hun Sen
PoliticalThai PM calls Cambodian Senate President to discuss peace. Hun Sen secretly records the 17-minute conversation.
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De-escalation Talks Fail
DiplomaticBilateral negotiations collapse. Cambodia rejects Thailand's proposals.
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Cambodia Announces ICJ Complaint
LegalCambodia says it will file complaint with International Court of Justice. Thailand rejects ICJ jurisdiction.
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Cambodia Deploys Elite Troops to Border
MilitaryCambodia moved significant forces including artillery toward border in response to soldier's death.
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Border Firefight Kills Cambodian Soldier
MilitaryThai and Cambodian forces exchanged gunfire at Chong Bok near Laos triborder. One Cambodian soldier killed.
Scenarios
Ceasefire Holds, Border Demarcation Process Begins
Discussed by: The Diplomat, South China Morning Post
The December ceasefire survives its first 72 hours, Thailand releases the 18 Cambodian POWs, and ASEAN observers successfully monitor compliance. Both countries agree to International Court of Justice mediation or a joint border demarcation commission to finally resolve the territorial ambiguity left by colonial-era maps. Thailand's January elections produce a government with a mandate to negotiate. Key indicator: ASEAN observer reports showing zero violations for two consecutive weeks. This requires political will from both sides and active US-ASEAN pressure to maintain momentum.
Ceasefire Collapses, Fighting Spreads Along Entire Border
Discussed by: UN High Commissioner for Human Rights, Britannica analysis
Like the July and October agreements, the December ceasefire fails within weeks. An incident—another landmine, a patrol crossing disputed territory, nationalist pressure from domestic politics—triggers renewed fighting. This time it spreads beyond the dozen previous flashpoints to the full 800-kilometer border. Regional powers including China and the US deploy more robust diplomatic pressure or sanctions. ASEAN's credibility as a regional security organization collapses. Key trigger: Either side claims a ceasefire violation during Thailand's January-February election period when nationalist rhetoric peaks.
Limited War, Then International Intervention Forces Settlement
Discussed by: Strategic analysts comparing to Cenepa War 1995
The conflict escalates into sustained conventional warfare with significant casualties and regional destabilization. Major powers—particularly the US and China, who have competing interests in Southeast Asia—impose economic consequences harsh enough to force both sides to accept binding international arbitration. A peacekeeping force from ASEAN or UN deploys to enforce a demilitarized buffer zone. Like the Ecuador-Peru conflict that produced the 1998 Brasília Accord, this results in a permanent settlement but only after the costs become unbearable. Key indicator: Fighting lasts more than 30 consecutive days with over 500 casualties.
Frozen Conflict Becomes the New Normal
Discussed by: Comparison to India-Pakistan Line of Control, analysis by Lowy Institute
Neither side wins militarily or accepts binding arbitration. The border becomes a permanent militarized zone with periodic flare-ups, occasional casualties, and routine ceasefire violations that never escalate into full war. Both countries maintain large troop deployments indefinitely. ASEAN observer missions become permanent fixtures. Border communities remain displaced for years. Like Kashmir's Line of Control, the dispute becomes a frozen conflict that defines the region for decades. This scenario requires both sides to conclude they can't win but also refuse to compromise.
Historical Context
Thailand-Cambodia Clashes Over Preah Vihear (2008-2011)
2008-2011What Happened
After Cambodia registered Preah Vihear as a UNESCO World Heritage Site in 2008, nationalist protests erupted in Thailand. Within a week, hundreds of soldiers from both countries stationed near the temple. Sporadic firefights between October 2008 and April 2011 killed at least 34 people. ASEAN's Secretary-General classified it as "open conflict."
Outcome
Short term: Multiple ceasefires brokered, all eventually violated. Fighting continued intermittently for three years.
Long term: Cambodia brought a second case to the ICJ in 2013 to clarify the 1962 ruling on surrounding land. Neither country fully demarcated the border. Tensions remained until 2025 flare-up.
Why It's Relevant
Same temple, same unresolved territorial ambiguity, same pattern of broken ceasefires. History suggests agreements without enforcement mechanisms don't last.
Cenepa War: Ecuador-Peru Border Conflict (1995)
January-February 1995What Happened
Ecuador and Peru fought for five weeks over territory disputed since a 1942 treaty. Multiple ceasefire attempts failed before the Itamaraty Agreement took effect February 28. Both sides claimed victory. A multinational observer mission (MOMEP) from guarantor countries—Argentina, Brazil, Chile, USA—monitored the truce.
Outcome
Short term: Ceasefire held with international monitors present. Casualties: dozens killed, significant military equipment destroyed.
Long term: Three years of mediation produced the 1998 Brasília Presidential Act, permanently settling the border. Required sustained diplomatic pressure and economic incentives from guarantor nations.
Why It's Relevant
Shows that monitored ceasefires can work but require years of follow-up diplomacy. ASEAN's observer role mirrors MOMEP, but lacks enforcement power or guarantee structure.
Kargil War: India-Pakistan Border Conflict (1999)
May-July 1999What Happened
Pakistani forces infiltrated Indian-controlled Kashmir, triggering two months of fighting. International pressure mounted as India advanced. President Clinton refused to intervene until Pakistan withdrew from Indian territory. Ceasefire declared late July after US diplomatic pressure and threat of broader war.
Outcome
Short term: Pakistan withdrew forces, suffering military and diplomatic defeat. Hundreds killed on both sides.
Long term: No permanent settlement. Line of Control remained disputed. India-Pakistan tensions continued with 2001-02 military standoff, though a 2003 LoC ceasefire reduced daily violations.
Why It's Relevant
Demonstrates that US pressure can halt fighting but doesn't resolve underlying territorial disputes. Trump's trade threats worked twice in 2025 but haven't produced lasting peace.