Why are Thailand and Cambodia Fighting?

President Donald Trump said Saturday that Cambodia’s prime minister and the acting prime minister of Thailand had agreed to meet immediately and quickly work out a ceasefire as he sought to end the conflict between the two Southeast Asian neighbors, which has entered a third day.

Thai and Cambodian forces attacked each other in the Thai province of Trat on Saturday, creating a new front in the battle over their shared border, in the deadliest clashes between the two Southeast Asian nations in more than a decade.

At least 34 people have died in the conflict, which began Thursday with an eruption of violence near Prasat Ta Muen Thom, an ancient temple claimed by both nations, after two months of tension.

Thailand and Cambodia are each negotiating trade deals with the United States, but it was unclear if Trump’s intervention would actually end the fighting.

China has also offered to mediate talks. It is the largest trading partner for Thailand and Cambodia, and has increased its influence in the region as governments in Southeast Asia are becoming wary of the United States.

The border tensions have contributed to a political crisis in Thailand: On July 1, a Thai court suspended the prime minister, Paetongtarn Shinawatra, because of comments she made about the dispute, which goes back decades. The conflict marks a split between Shinawatra’s father and Cambodia’s leader, whose decades-long relationship had been the glue holding the two neighbors together despite the intractable border dispute.

What started this conflict?

Each nation accused the other of firing first on Thursday.

The Thai army said that Cambodia had fired rockets into civilian areas in four Thai provinces, prompting Thailand to send F-16 fighter jets to strike targets in Cambodia.

Cambodian officials said that Thai soldiers had opened fire on Cambodian troops first, at Prasat Ta Muen Thom, a temple claimed by both nations. They said Cambodian forces returned fire some 15 minutes later.

In Thailand, at least 13 civilians and seven soldiers have been killed. In Cambodia, there have been at least 13 deaths, including those of five soldiers.

More than 131,000 people in Thailand have evacuated from areas along the border, while in Cambodia, 35,000 people have fled their homes.

Who is working on a ceasefire?

In a post on Truth Social on Saturday, Trump said he spoke by phone with Cambodia’s leader, Hun Manet, and Thailand’s acting prime minister, Phumtham Wechayachai.

The president said that he told both leaders that it was inappropriate to “get back to the ‘Trading Table’ with the United States “until the fighting STOPS.” Thailand and Cambodia are both negotiating trade deals with the United States.

“They will hopefully get along for many years to come,” Trump wrote. In an earlier post, he said he was “trying to simplify a complex situation!”

It was unclear whether Trump’s intervention would lead to a genuine breakthrough. Cambodia said Friday that it had agreed to a ceasefire brokered by Malaysia but accused Thailand of reneging on the deal. Thailand responded by saying that any ceasefire had to be based on “appropriate, on the ground conditions,” and that Cambodia’s continued attacks showed a lack of good faith.

On Friday, representatives of Cambodia and Thailand spoke at an emergency meeting of the United Nations Security Council, with each side accusing the other of escalating the violence.

On Thursday, a spokesperson for China’s Foreign Ministry said that Thailand and Cambodia were China’s “friendly neighbors,” adding that Beijing had been working to facilitate talks.

What are the origins of the border tensions?

The ownership of Prasat Ta Muen Thom is disputed by the two countries. Hun Sen claimed in a social media post that a Thai military commander had “started this war” by ordering the closure of the temple on Wednesday, and opening fire on Cambodian troops the next day.

Thailand has accused Cambodia of starting the conflict.

The temple is in the Surin province of Thailand, on the disputed border with Cambodia, and people there speak Khmer as well as Thai, highlighting the cultural overlap with Cambodia, where Khmer is the official language. The province is known for ruins from the Khmer Empire, which lasted from the ninth to the 15th century. One such ruin is Prasat Ta Muen Thom.

Arguments about where the border should be and who owns the temples in the region have led to decades of disputes.

In 1962, the International Court of Justice awarded Cambodia sovereignty over the Preah Vihear Temple, another temple about 95 miles away. In 2013, the court, the top judicial body of the United Nations, tried to clarify the 1962 decision. It said that Cambodia had sovereignty over the immediate area around that temple, but it left unresolved who controlled a larger disputed area.

The two countries have had occasional military clashes and nationalist rivalries for hundreds of years. The border disputes can be traced to a 1907 map created during French colonial rule in Cambodia. The two countries interpret the map differently.

Military fighting has broken out intermittently since 2008, but the last time that a major clash turned deadly was in 2011.

Why was Thailand’s prime minister suspended?

In June, Paetongtarn spoke by phone to Hun Sen, Cambodia’s de facto leader, to discuss the escalating border tensions. Hun Sen has had close ties to her father, Thaksin Shinawatra, a former prime minister of Thailand and the leader of a powerful political dynasty, as well as one of the country’s richest men.

Hun Sen posted a recording of their call, in which Paetongtarn seemed to disparage Thailand’s powerful military and take a deferential tone. She called Hun Sen “uncle” and told him that she would “arrange” anything he wanted.

In response, thousands of protesters took to the streets of Bangkok to express their outrage. Although Paetongtarn apologized, she has faced pressure to resign.

In early July, a Thai court suspended her.

This article originally appeared in The New York Times.