Border clashes have once again shaken the border between Thailand and Cambodia, one of the hottest zones in Southeast Asia, definitively breaking the fragile peace agreement reached just a few months ago under the auspices of U.S. President Donald Trump. The resumption of hostilities represents a severe setback to international diplomatic efforts and rekindles a historical deadly conflict that seemed, at least temporarily, contained.
This Monday, the Thai army launched airstrikes against Cambodian military infrastructure, a day after both forces began exchanging fire along their common 817-kilometer border. According to Bangkok, the aerial operations were a direct response to a previous attack by Cambodian troops.
The spokesperson for the Thai army, General Winthai Suvari, stated that Cambodian forces opened fire early Monday morning on Thai positions, causing the death of at least one soldier and injuring four others. Cambodian authorities later reported that four civilians had died and nine were injured during Thai airstrikes in the northern provinces of Preah Vihear and Oddar Meanchey.
Mass evacuations on both sides of the border have been carried out. In Thailand, 385,000 civilians were relocated to safe shelters.
"The airstrikes targeted exclusively military infrastructure, including weapon depots, command centers, and logistical routes identified as direct threats," stated the Royal Thai Air Force (RTAF) in an official statement.
The text added that military authorities had detected the mobilization of heavy weaponry, the repositioning of combat units, and the preparation of armed support by the Cambodian side, actions that, according to Bangkok, increased the risk of further escalation in the border area.
From Phnom Penh, however, a different version is given. The Cambodian Ministry of Defense denied initiating hostilities and stated that it was Thailand who directly launched their airstrikes around five in the morning. "True to the spirit of respecting existing agreements and resolving disputes peacefully in accordance with international law, Cambodia did not retaliate and continues to monitor the situation with utmost caution," stated Cambodian authorities.
On Sunday, both sides had already accused each other of provoking the initial clashes, following an artillery exchange that lasted about 35 minutes at various points along the northeastern border. As a result, both Thailand and Cambodia ordered the preventive evacuation of numerous civilians from border towns, fearing an intensification of the fighting.
The latest clash occurs in a context of growing diplomatic tension. Weeks ago, Thailand requested a UN investigation into the alleged systematic use of landmines by Cambodia within Thai territory, which in November left several soldiers injured. Following these allegations, Thai Prime Minister Anutin Charnvirakul announced the suspension of the peace joint declaration signed in October in Kuala Lumpur, during a ceremony led by Donald Trump.
"Thailand is determined to defend its sovereignty, in accordance with international norms and our right to self-defense," declared the Thai Prime Minister on Monday afternoon, also announcing new "military operations" to respond to "all incidents."
This conflict escalated severely last July when the deadliest border clashes in over a decade erupted, resulting in nearly fifty deaths and around 300,000 displaced persons. In that episode, both sides exchanged accusations of war crimes. Phnom Penh denounced that the Thai army had used cluster bombs - weaponry prohibited by UN international treaties - in at least seven border areas within Cambodian territory.
After five days of intense fighting, a ceasefire was signed in August negotiated by Malaysian Prime Minister Anwar Ibrahim and the American Trump, who threatened both countries with new tariffs if the artillery exchange did not cease. With the peace agreement signed in October, the US president claimed a new diplomatic achievement, presenting himself once again as a key player in resolving international conflicts.
The dispute between Thailand and Cambodia dates back over a century when France, which occupied Cambodia until 1953, first drew the land border. Cambodia was ruled by authoritarian leader Hun Sen for almost four decades before he handed over power to his son, Hun Manet, in 2023. Currently, Hun Sen currently presides over the Senate and holds significant power in the country.
Phnom Penh has rejected the division drawn by the French and has requested a new ruling from the International Court of Justice (ICJ), the UN's principal judicial organ, on the disputed areas. However, Bangkok does not recognize the ICJ's jurisdiction and also claims some areas controlled by Cambodia, stating that they were never rigorously demarcated.
The first armed clash of the year took place last May when a Cambodian soldier died in an isolated confrontation. Following that incident, tensions escalated and also led to a serious internal political crisis in Thailand. The then Prime Minister, Paetongtarn Shinawatra, was heavily criticized after having a phone conversation with Hun Sen, an old ally of her family, triggering a wave of massive protests in Bangkok.
Ultimately, the Constitutional Court suspended Shinawatra from her duties, accusing her of "dishonesty" and "ethical violations," in an episode that highlighted how the border conflict has transcended the military realm to become a factor of regional political instability.