Thailand Launches Airstrikes Amid Border Dispute with Cambodia

On July 24, 2025, Thailand and Cambodia entered open conflict over a long-term border dispute, exchanging gunfire and airstrikes in the deadliest clash between the two countries in over a decade. These developments, which follow months of simmering tensions and an earlier skirmish between troops on May 28, 2025, represent the sharpest escalation in conflict between Southeast Asian countries in recent years and a critical litmus test for the Association of Southeast Asian Nations (ASEAN).

Q1: What sparked the conflict, and why now?

A1: According to Thai government sources, Cambodian forces opened fire on Thai soldiers and facilities near the Prasat Ta Muen Thom temple complex located along the Thai-Cambodia border early on July 24. The two sides in turn exchanged artillery fire, with Cambodia also firing BM-21 rockets at other locations along the border and Thailand scrambling F-16 fighter jets to bomb military targets in Cambodia. Thailand has since confirmed at least 13 civilian deaths as a result of Cambodian attacks, with no information thus far on the number of casualties from the Cambodian side. Cambodia, for its part, has claimed that Thai soldiers were the first to open fire, and has accused Thailand of attacking both military and civilian targets.

This escalation of conflict comes a day after Thailand recalled its ambassador to Cambodia and vowed to expel Cambodia’s ambassador in Bangkok following a landmine explosion that injured five Thai soldiers along the border. Thailand had also pledged to close border crossings with its neighbor.

Q2: What is the border dispute about?

A2: Border disputes have long been a flashpoint in Cambodia-Thailand relations. Tensions erupted previously in 2008, following Cambodia’s efforts to register the Preah Vihear temple complex, which sits at the border between the two countries, as a UNESCO World Heritage Site. The following years saw both countries increase their security presence in the areas surrounding the temple and other locations adjacent to the border, including the Ta Muen Thom temple complex at the heart of recent clashes. The expanded presence of both Thai and Cambodian security forces at the border in turn led to multiple deadly skirmishes throughout 2008 and 2011, with the International Court of Justice in 2013 eventually awarding the lands around Preah Vihear to Cambodia while calling for Thailand to withdraw its forces from the area. But the court left unresolved the status of other areas under dispute, leading to sustained tensions to this day.

Q3: What happens next?

A3: The next few days will be critical for de-escalation. Prime Minister Hun Manet of Cambodia has called for a meeting of the United Nations Security Council to address the crisis, describing Thai forces’ actions as “unprovoked, premeditated and deliberate attacks” and characterizing his country’s response as “self-defense in order to safeguard Cambodia’s sovereignty and territorial integrity.” Thailand’s Paetongtarn Shinawatra, currently suspended from her office as prime minister, has been similarly critical of her counterparts in Phnom Penh, claiming that Cambodia initiated the violence. These conflicting accounts not only echo the events of February 2011 following violent border clashes between Cambodia and Thailand, but also point to the urgent need for independent fact-finding from neutral parties or other ASEAN member states to resolve the crisis. 

The dispute is also likely to bleed into domestic politics in each country. An earlier incident in the border row already led to the suspension of Thai Prime Minister Paetongtarn Shinawatra on July 1, following the leaked recording of a phone call she held with Cambodian Senate President and former Prime Minister Hun Sen. Thailand now faces a leadership vacuum, with a fragile Pheu Thai–led coalition government helmed by acting prime minister Phumtham Wechayachai. Whether recent developments will allow Paetongtarn or Phumtham space to consolidate their party’s hold on government, or whether the Thai military or affiliated political parties will use the crisis to push for a change in power, remains to be seen.

How the current crisis will impact domestic politics in Cambodia is less clear. Hun Sen has deliberately inflamed the crisis, likely in a bid to shore up domestic political support for his government and the premiership of his son, Hun Manet, amid a flagging local economy. But while stirring up nationalist fervor might be good for short-term domestic political gains, the outbreak of deadly border clashes risks escalating the situation beyond the immediate control of both sides.

Q4: How have regional and international partners responded?

A4: Thus far, responses from Thailand and Cambodia’s neighbors in ASEAN have been mixed. Current ASEAN Chair and Prime Minister of Malaysia Anwar Ibrahim has called for a cessation of hostilities and pledged to speak with his counterparts in Thailand and Cambodia, noting that “peace is the only option available.” Meanwhile, Singapore’s foreign ministry issued a statement calling for the de-escalation of tensions through diplomatic means, echoing a July 2 statement by Singapore’s Prime Minister Lawrence Wong calling for restraint and dialogue. Other ASEAN member states, including the Philippines and Vietnam, have also expressed concern over current tensions through statements issued by their respective foreign ministries. Notably missing, however, has been a direct response from Indonesia, traditionally an informal leader within ASEAN. President Prabowo Subianto has yet to publicly address the recent spate of violence, in spite of the fact that Indonesia played a key role in de-escalating tensions during the 2011 crisis during its then-tenure as ASEAN chair.

The individual and collective responses of ASEAN member states to the border conflict will be a litmus test for the organization, at a time when external pressures and the threat of great power competition have divided the region. Even ASEAN’s most strident critics recognize the important role that the organization has played in trust-building and preventative diplomacy between member states. Failure by ASEAN to take an active role in resolving the current crisis would further shake confidence in the organization and its centrality in regional affairs.

International partners have also responded to the crisis. Japan, a key economic partner of both Cambodia and Thailand, expressed deep concern over the clashes and called for both sides to exercise maximum restraint. The European Union issued a statement calling for de-escalation and dialogue through its spokesperson for foreign affairs and security policy. And China’s foreign ministry issued a statement calling for dialogue and pledged to “promote talks for peace in our own way and play a constructive role in promoting de-escalation.”

Q5: How has the United States responded?

A5: The United States, despite viewing Thailand as an ally, has been slower to respond. The Trump administration issued brief statements through the embassies in Cambodia and Thailand urging U.S. citizens to avoid affected border areas, but otherwise has not publicly addressed the emerging crisis beyond calling for a cessation of hostilities during a U.S. State Department press briefing. The recent reorganization of the State Department, including the demolition of the Office of Multilateral Affairs that managed U.S. engagement with ASEAN, has removed some of the expertise that would normally inform Washington’s response to the crisis. There is no confirmed assistant secretary of state for East Asia and the Pacific nor a permanent director for Southeast Asia at the National Security Council, limiting the channels to rapidly elevate regional developments to the attention of and provide advice to Secretary of State/National Security Advisor Marco Rubio.

As for the secretary himself, Rubio has a longstanding interest in Cambodia and has been critical of the ruling regime. But U.S.-Thai relations have also hit a rough patch recently, with the State Department—presumably at the secretary’s direction—sanctioning Thai officials involved in the sudden deportation of Uyghur asylum seekers to China earlier this year. The crisis also comes just after Rubio’s first trip to Southeast Asia for the ASEAN Regional Forum, during which he was dogged by concerns about U.S. reliability. That means the regional elites will judge the speed and effectiveness of the U.S. response partly on whether it reinforces or contradicts their fears of U.S. retrenchment.

Andreyka Natalegawa is an associate fellow for the Southeast Asia Program at the Center for Strategic and International Studies in Washington, D.C. Gregory B. Poling is a senior fellow and director for the Southeast Asia Program and the Asia Maritime Transparency Initiative at CSIS.