A Short History of Thai-Cambodian Relations

First, my condolences to everyone who has suffered loss from this conflict.

I believe everyone was just as shocked as I was when the news came. At first I wasn’t sure whether I had missed something. I knew a little that we had disputes, but I didn’t think they ran this deep. So this post is a short summary of the relationship (as I understand it).

Thai-Cambodian relations are a story full of complexity and historical wounds going back to the Angkor empire. Shaped by the influence of both Siam and Vietnam, and carrying ethnic memories of feeling dominated, the relationship between the two countries has never stayed smooth for long.

When France colonized the region in the 19th century, Cambodia saw France more as a “liberator” from the pressure of its neighbors than as an invader. This created completely different views of Thai-Cambodian relations, and became one of the roots of the suspicion we still see today.

After World War II, Thailand and Cambodia formally established diplomatic relations in 1950, but the relationship was full of mistrust in the Cold War era. Thailand chose the side of the free world and became a close ally of the US, while Cambodia’s Prince Sihanouk tried to keep a non-aligned policy. The major dispute was the Preah Vihear temple, which Cambodia took to the International Court of Justice in 1960. The court ruled in Cambodia’s favor in 1962, which upset many Thais and became a wound that keeps getting dug up as an issue.

In the Cold War period, and from 1975 onward, the relationship grew more complicated when Cambodia fell under the rule of the Khmer Rouge. Thailand took in hundreds of thousands of refugees crossing the border. At the same time, there were allegations that Thailand might have helped Khmer Rouge forces. Although the evidence is murky, rumors and Cold War distortions made the matter widely discussed.

After the Cold War, the relationship began to recover under the policy of “turning battlefields into marketplaces.” The Thai-Cambodian Friendship Bridge (Aranyaprathet to Poipet) in 1992 was a symbol of new cooperation. But the 2003 riot in Phnom Penh against Thais, triggered by a rumor about a Thai actress, was a reminder that a small misunderstanding can escalate into cross-border violence. I see this as a very strong pattern in this relationship, as if it is always waiting for some trigger to flare up.

In 2008 to 2011, tension around Preah Vihear erupted again after Cambodia had the temple listed as a World Heritage Site. Both sides reinforced their forces, and there were several military clashes. A good relationship was once again at a fragile point.

In the current round, many people are familiar with the leaked audio clip on the Thai side and the Cambodian side. But the key event that began forming into the present situation started on May 28, 2025, when Thai and Cambodian soldiers clashed in the Emerald Triangle area, leaving one Cambodian soldier dead. Each side accused the other of firing first. Although the two army commanders later held talks to control the situation, the tension dragged on and grew more intense.

In June, negotiations to ease the conflict failed. Thailand began reinforcing along the border and accused Cambodian civilians of encroachment. Cambodia retaliated by banning imports of Thai fruit and TV dramas. Meanwhile, the Thai Ministry of Defense authorized the army to manage border checkpoints strictly, leading to closures on both sides. Thailand started by closing the Chong Sai Taku checkpoint in Buriram, and Cambodia followed by closing the Bun Chup Kokee and Chong Chum crossings in Oddar Meanchey and Anlong Veng.

In mid-July, the relationship worsened when several Thai soldiers were wounded by newer PMN-2 landmines in the Emerald Triangle area. Thailand said this was evidence of a violation of the Ottawa Treaty and an infringement of sovereignty, and so announced further border closures and put its military on the highest readiness.

A few days later, it turned into the full-scale fighting you’ve seen in the news.

I’ve also noticed that the 2025 border conflict has been fought not only on the real battlefield but also in the “information arena.” Fake news such as the claim that “the Cambodian army shot down a Thai F-16 fighter” spread quickly online. Perhaps it’s because social media prioritize emotionally charged content over the truth: the more dramatic or angering the content, the faster it gets passed on.

This isn’t new. If we look back at the events of 2003, or at past nationalist campaigns, we can see that what used to work through radio, newspapers, or speeches has been replaced by the speed and power of digital platforms. When people hit share without checking, the truth can be drowned out by belief and emotion.

So this is not just a conflict between states. It is a challenge for ordinary people.

I mostly see conflicts like this as having escalated from big players quarrelling, with the impact landing on ordinary people.

I have several Cambodian friends. Even when something like this happens, I have to try to separate conflict between states from personal relationships.

Because when we take in news, feel strongly about it without questioning, and share it right away, we may become a small cog that spreads false information without realizing it, and helps hatred grow.

What matters is looking back at history and understanding the complexity of Thai-Cambodian relations. I’d like everyone to see this pattern together: a misunderstanding of just a split second can lead to a rift deeper than we think. In a world where information travels faster than bullets, calm and careful thinking may be the most powerful armor.

However, the rift has now turned into fighting. In this round, there have been attacks and violence against civilians who have nothing to do with the fighting, and against medical facilities, which should be protected. These are acts that seriously damage peace and trust between countries. Thais and the international community should stand firm in condemning attacks of this kind, as a reminder that war without limits and without respect for civilian lives is something the world cannot accept.