Why Thailand and Cambodia Are Fighting

New Clashes Erupt on the Thailand-Cambodia Border. Here’s What to Know.The latest violence comes months after President Trump helped mediate a cease-fire between the two nations.Families gathered at a temporary shelter in Buriram province, Thailand, on Monday after clashes along the Thailand-Cambodia border.Credit...Sarot Meksophawannakul/Thai News Pix, via Getty ImagesDec. 8, 2025, 10:53 a.m. ETThailand and Cambodia have again accused each other of firing first in a fresh round of fighting along their restive border, weeks after the two countries signed an agreement, which President Trump helped mediate, making a commitment to peace in their longstanding dispute.Thailand bombed Cambodian targets on Monday after it said that a Thai soldier had been killed in cross-border firing. Cambodia said that four civilians had been killed in two border provinces, although it was not immediately clear if the Thai strikes had killed them.The fighting is a sharp escalation of tensions between the two Southeast Asian nations. In July, five days of fighting across their shared border killed at least 40 people and displaced hundreds of thousands. They agreed to a cease-fire in late July, brokered in part by President Trump, but Thailand suspended peace talks in November.What happened at the border?Thailand said that it used F-16 fighter jets to bomb Cambodian military targets on Monday, and Cambodia confirmed that Thai jets had attacked around 9 a.m.Thailand said it was retaliating against an attack by Cambodia earlier in the day that killed at least one Thai soldier and injured eight others in a border province. It was not immediately clear how much damage the Thai airstrikes had caused.“If you want the fight to stop, go tell the aggressor,” Anutin Charnvirakul, Thailand’s prime minister, said on Monday.Cambodia said four civilians had been killed and nine others injured by Thai fire. Hun Sen, the de facto leader of Cambodia, urged restraint. “All frontline forces have to remain patient,” he wrote on his Facebook page on Monday.About half a million people have been displaced by this round of fighting. The Thai military said that 438,000 people had gone to shelters, and Cambodian officials said that tens of thousands of people had moved away from the border.The hostilities followed a cross-border exchange of fire on Sunday that did not appear to be deadly but that escalated tensions, with both sides blaming each other for starting the fighting.What happened to the cease-fire?After the previous flare-up of violence in July, the two countries agreed to a cease-fire that was brokered by Mr. Trump and Malaysia’s prime minister, Anwar Ibrahim.At the time, officials in Thailand and Cambodia had also accused the other side of firing first, and the two countries exchanged gunfire and shelled each other for five days. At least 40 people were killed and hundreds of thousands were displaced.After the cease-fire, the two countries continued to trade accusations.In November, undermining Mr. Trump’s efforts to cast himself as a global peacemaker, Thailand pulled out of peace talks with Cambodia after two Thai soldiers were injured by a land mine in a disputed border area.In a statement on Monday, Mr. Anwar said that “our region cannot afford to see longstanding disputes slip into cycles of confrontation.”The conflict between Thailand and Cambodia is driven by nationalist rivalries and long-running border disputes, and fighting has broken out intermittently since 2008. Before the clashes in July, the last time that a major incident turned deadly was in 2011.ImageCambodian soldiers at a military base in 2011. The border between Thailand and Cambodia has been a frequent source of conflict between them.Credit...Khem Sovannara/Agence France-Presse — Getty ImagesMuch of the conflict comes down to disagreements over the nearly 500-mile-long boundary between the two nations, large parts of which are undefined.Those disagreements can be traced to a 1907 map that was created during French colonial rule and that Thailand and Cambodia interpret differently. Some of the most tense areas along the border are home to centuries-old temples.Arguments about where the border should be, and who owns the temples in the region, have led to decades of friction.Prasat Preah Vihear and Prasat Ta Muen Thom, both Khmer-era Hindu temples about 95 miles apart, are two of the key sites where tensions flared in July. On Monday, the Thai army said that one of its airstrikes had struck a radio tower near the Preah Vihear temple.Is it safe to travel to Thailand and Cambodia?On Monday, the U.S. Embassy in Thailand and the U.S. Embassy in Cambodia both urged Americans to avoid traveling within 50 kilometers (about 30 miles) of the Thai-Cambodia border. The embassies both said in statements that they were monitoring reports of a “significant escalation” in the fighting and that the situation remains “volatile.”Amelia Nierenberg is a Times reporter covering international news from London.SKIP