General information
Part of Conflict: Cambodia (Kampuchea) - Thailand
Date of first stated goals of incompatibility: 1953-12-31
Comment on date of first stated goal of incompatibility: When the Cambodia gained independence from France in 1953, Thai polices forces occupied the ancient Temple of Preah Vihear. Cambodia immediately claimed to have sovereign right over the Temple and negotiations between the two parties were held. The right to the territory had been disputed by Cambodia and Thailand even before 1953 but this was the first time Thailand had occupied the Temple since the World War II and the first time Cambodia claimed the territory as a sovereign country.
Date of first use of armed force: 1965-06-01
Comment on date of first use of armed force: There is limited reliable information on the developments after the International Court of Justice’s decision to support Cambodia’s claim of having sovereign right of the Temple and its surrounding territory. The first recorded armed violence related to border disputes between Thailand and Cambodia was in June 1965 when Thai and Cambodian forces allegedly clashed in heavy fighting. It is possible that armed violence was used earlier than this date.
First Battle Related Death: 1975-12-14
Comment on First Battle Related Death: A number of clashes between Thai and Cambodian forces (Khmer Rouge) took place during 1975. Several fatalities were reported in clashes between Thai border police and Cambodian forces on 12-15 December. There is limited reliable information regarding the disputed border and its related clashes between Thai and Cambodian forces. It is therefore possible that the first battle related death occurred earlier than this date. The clashes in mid December was however the first recorded incident of battle related death in this conflict.
Date when dyad reached 25 battle releated deaths: 1977-12-31
Comment on date when dyad reached 25 battle related deaths: The fighting between Thai forces and Cambodian forces along the border escalated in 1977. Clashes were reported at a number of locations along the border, but the most notable ones took place in the Prachinburi province, located east of Bangkok. There is limited reliable information regarding the disputed border and its related clashes between Thai and Cambodian forces. It is therefore possible that the conflict reached 25 battle related deaths before this date.
Conflict issues
Annual information
This section contains annual information systematically collected by the UCDP.
1975
| Estimated Fatalities | |
|---|---|
| High | 1 |
| Best | 1 |
| Low | 0 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
1977
| Estimated Fatalities | |
|---|---|
| High | 25 |
| Best | 25 |
| Low | 0 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
1978
| Estimated Fatalities | |
|---|---|
| High | 25 |
| Best | 25 |
| Low | 0 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
1995
| Estimated Fatalities | |
|---|---|
| High | 31 |
| Best | 7 |
| Low | 7 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
1997
| Estimated Fatalities | |
|---|---|
| High | 4 |
| Best | 0 |
| Low | 0 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
1998
| Estimated Fatalities | |
|---|---|
| High | 12 |
| Best | 12 |
| Low | 12 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
1999
| Estimated Fatalities | |
|---|---|
| High | 0 |
| Best | 0 |
| Low | 0 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
2008
| Estimated Fatalities | |
|---|---|
| High | 2 |
| Best | 2 |
| Low | 2 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
2009
| Estimated Fatalities | |
|---|---|
| High | 5 |
| Best | 2 |
| Low | 2 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
2011
| Estimated Fatalities | |
|---|---|
| High | 36 |
| Best | 29 |
| Low | 29 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
2012
| Estimated Fatalities | |
|---|---|
| High | 0 |
| Best | 0 |
| Low | 0 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
2013
| Estimated Fatalities | |
|---|---|
| High | 0 |
| Best | 0 |
| Low | 0 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
2015
| Estimated Fatalities | |
|---|---|
| High | 0 |
| Best | 0 |
| Low | 0 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
2023
| Estimated Fatalities | |
|---|---|
| High | 0 |
| Best | 0 |
| Low | 0 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
2025
| Estimated Fatalities | |
|---|---|
| High | 442 |
| Best | 252 |
| Low | 249 |
Secondary Warring Support:
Side A (Government of Cambodia (Kampuchea)): n/a
Side B (Government of Thailand): n/a
Peace agreements
Name of peace agreement: Kuala Lumpur Peace Accord
Date when warring parties signed the agreement: 2025-10-26
Dyad Archive
This section contains annual information no longer systematically collected by the UCDP.
1975 Dyad Archive
Negotiations: NO
Victory: NO
Terminated: NO
1977 Dyad Archive
Comment on Yearly Battle Related Deaths: The number of battle-related deaths in this dyad is unclear, but activity at the least surpassed 25 battle-related deaths.
Comment on Active: Clashes took place at several locations along the border throughout the year. The most notable clashes took place in the Prachinburi province, located east of Bangkok.
Negotiations: NO
Victory: NO
Terminated: NO
1978 Dyad Archive
Comment on Yearly Battle Related Deaths: The number of battle-related deaths in this dyad is unclear, but activity at the least surpassed 25 battle-related deaths.
Comment on Active: Border clashes took place at a number of locations along the Thai-Kampuchean border. Killings were reported in the border town Non Sao-Ae and in villages in the Buriran and Ban Krut districts neighbouring the border.
Negotiations: YES
Comment on Negotiations: Negotiations were held by the parties in the Kampuchean capital Phnom Penh on 30 January – 2 February. The outcome of the talks consisted of an agreement to implement the joint communiqué drafted on 31 October 1975. The communiqué aimed to normalise relations, resume economic and trade relations and establish diplomatic relations in terms of exchanging ambassadors.
No real progress on implementing the joint communiqué had been achieved at the end of 1978.
Victory: NO
Terminated: YES
Type of termination: Other
Date of termination: 1978-12-31
Comment on Termination: During the second half of 1978, the Kampuchean regime faced an increased threat from Vietnam and in December the fighting escalated along the Kampuchean-Vietnamese border. The Kampuchean regime’s focus shifted from the Thai border to the Vietnamese border and the border clashes with Thailand eventually ceased. The question of the exact location of the border between Kampuchea and Thailand was, however, not solved. The fighting along the Kampuchean-Thai border continued during the following years, but was then related to the conflict over governmental power in Cambodia.
1995 Dyad Archive
Negotiations: NO
Victory: NO
Terminated: NO
1997 Dyad Archive
Negotiations: NO
Victory: NO
Terminated: NO
1998 Dyad Archive
Negotiations: NO
Victory: NO
Terminated: NO
1999 Dyad Archive
Negotiations: NO
Victory: NO
Terminated: NO
2008 Dyad Archive
Negotiations: NO
Victory: NO
Terminated: NO
2009 Dyad Archive
Negotiations: NO
Victory: NO
Terminated: NO
2011 Dyad Archive
Comment on Active: 2011 proved to be the most violent year in more than three decades as the interstate conflict between Cambodia and Thailand once again became active for the first time since 1978. The conflict escalated on 4 February when Thai and Cambodian troops exchanged fire in the vicinity of the Preah Vihear temple. It was unclear who provoked the clash which ended with a truce later the same day. However, the truce proved to be fragile as the movement of Thai tanks was enough to provoke renewed clashes. For three successive days, Thai and Cambodian troops exchanged fire, despite new attempts to end the violence through a ceasefire agreement on 5 February. Both sides suffered fatalities and three civilians were reportedly killed as stray bullets and rockets hit adjacent settlements. In addition, the skirmishes left thousands of civilians displaced. Despite the ostensible step towards an observation mission, Thailand proved to be resistant during the following meeting, thus continuing to stall the talks. The negotiations regarding the mission reached an inevitable deadlock in late April as Thailand demanded Cambodia to withdraw its troop before deploying Indonesian observers. As the attempt to solve the conflict faded with the Thai demand, the Thai-Cambodian relation deteriorated and new fighting erupted on 22 April in the Thai province Surin, thus the conflict had spread beyond the Preah Vihear area. Cambodia had been occupying the Ta Krabei temple in Surin and the new clashes started when Cambodian troops deployed in the area fired at Thai troops. A ceasefire was reached the same day but was quickly broken as fighting continued until 5 May. During the skirmishes, both parties accused each other of violating international law by deliberately targeting civilians. At the ASEAN summit in Jakarta on 3 May, Thailand refused to sign an agreement regarding observers, thus hampering progression once more. During this second round of fighting, both parties suffered casualties. In addition, an estimate of 45 000 people had been displaced.
Negotiations: NO
Comment on Negotiations: In order to settle the prolonged dispute between the two states, the UN Security Council assigned the Association of Southeast Asian Naitions ( ASEAN )to resolve the conflict. A step towards an increased regional involvement was taken after the February clashes when the Security Council decided to hold a three-party talk including Indonesia (ASEAN chairmanship in 2011), Thailand and Cambodia, where both parties expressed their wish for a peaceful solution. The meeting resulted in Cambodia stressing the importance of ASEAN observers at the border while Thailand showed a resilient stance regarding such a request. However, the Thai foreign ministry later changed its mind and decided to discuss the deployment of outside observers.
Despite the ostensible step towards an observation mission, Thailand proved to be resistant during the following meeting, thus continuing to stall the talks. The negotiations regarding the mission reached an inevitable deadlock in late April as Thailand demanded Cambodia to withdraw its troop before deploying Indonesian observers. As the attempt to solve the conflict faded with the Thai demand, the Thai-Cambodian relation deteriorated and new fighting erupted on 22 April in the Thai province Surin, thus the conflict had spread beyond the Preah Vihear area. Cambodia had been occupying the Ta Krabei temple in Surin and the new clashes started when Cambodian troops deployed in the area fired at Thai troops. A ceasefire was reached the same day but was quickly broken as fighting continued until 5 May. During the skirmishes, both parties accused each other of violating international law by deliberately targeting civilians. At the ASEAN summit in Jakarta on 3 May, Thailand refused to sign an agreement regarding observers, thus hampering progression once more. During this second round of fighting, both parties suffered casualties. In addition, an estimate of 45 000 people had been displaced.
Victory: NO
Terminated: YES
Type of termination: No or Low Activity
Date of termination: 2011-12-31
Comment on Termination: The conflict was terminated in 2011 due to a lack of activity in 2012.
2012 Dyad Archive
Terminated: NO
2013 Dyad Archive
Negotiations: NO
Victory: NO
Terminated: NO
2015 Dyad Archive
Terminated: NO
2023 Dyad Archive
Terminated: NO
2025 Dyad Archive
Negotiations: YES
Comment on Negotiations: A ceasefire was negotiated, and implemented on the 28th of July.
On October 26th the Cambodian and Thai governments signed the Kuala Lumpur Peace Accord. The parties reiterated their commitment to peace, refrainment from use of force, and their respect for international boundaries. They also agreed to the establishment of an observation team consisting of personnel from ASEAN (Association of Southeast Asian Nations) member states, to ensure the implementation and effectiveness of the ceasefire. The parties also agreed to partake in confidence-building measures, aiming to restore and maintain mutual trust as well as decrease negative public sentiment. Furthermore, they also reaffirmed their commitment to solving the border dispute through peaceful means and international law, and using the established border committees to address such issues. The agreement was signed by both the governments of Thailand and Cambodia, as well as Malaysia and the United States who were present as witnesses.
After clashes had resumed again, a new ceasefire was brokered and implemented on the 27th of December
Victory: NO
Terminated: NO
Type of termination: Not terminated
