The border disputes can be traced back to a 1907 map created during French colonial rule in Cambodia. The map was the basis of Cambodia’s claims to certain parts of the border, but its vagueness led to conflicting interpretations, and Thailand contested it. The countries tried to resolve the dispute diplomatically, but the issue was never settled completely, even after transnational bodies like the International Court of Justice intervened in 1962. At stake were areas like centuries-old historical temples. Military fighting has broken out intermittently since 2008. The last time tensions turned deadly was in 2011, when the fighting focused on a jungle border area including ancient temples to which both sides had laid claim. Each side blamed the other for starting and prolonging the fighting. The two nations declared a cease-fire after seven days of fighting killed at least 15 people and displaced tens of thousands of civilians. That same year, a United Nations court ordered the two nations to withdraw troops and establish a demilitarized zone, but the court left unresolved who would control a larger disputed territory, where troops kept clashing. May 28, 2025 The border dispute worsened again earlier this year. In a skirmish between the two countries, a Cambodian soldier was killed. The soldier’s death brought the relations between the countries to the lowest point in years. Prime Minister Paetongtarn Shinawatra of Thailand spoke with Cambodia’s de facto leader, Hun Sen. The call was meant to resolve the tensions between the two countries. A recording of the call that Mr. Hun Sen posted to his Facebook page ignited an outcry in Thailand. Ms. Paetongtarn urged him to ignore the Thai military, referring to it as “the opposite side,” and called him “uncle.” She also offered to “arrange” anything that he wanted. Her comments drew condemnation from Thai lawmakers, both in her coalition and the opposition. They said she appeared to disparage her own country’s military and took too much of a deferential tone with another country’s leader. Thai leaders called on her to resign. Thailand’s Constitutional Court suspended Ms. Paetongtarn, accepting a petition to the court brought by a group of senators who sought her removal and accused her of violating ethics standards in her call with Mr. Hun Sen. She apologized again and said personal gain had not been the purpose of her conversation with Mr. Hun Sen. A Thai soldier lost his right leg in a land mine explosion. Thailand said it would downgrade diplomatic relations with Cambodia, recalling its ambassador to Cambodia and expelling Cambodia’s ambassador.