Cambodia – Thailand Tensions: Political Motives, the International Chessboard, and Future Scenarios

1. Introduction: A Difficult-to-Heal Rift in Neighborly Relations

Relations between Cambodia and Thailand have always been volatile, but one of the persistent “triggers” is the border dispute around the Preah Vihear temple and adjacent areas. This is not merely a matter of a few square kilometers of land; it is steeped in historical factors, national pride, and the internal political calculations of both governments.

In recent years, sporadic military clashes have occurred, causing casualties and forcing thousands of residents along the border to evacuate. Despite repeated calls for restraint from ASEAN and the international community, tensions have once again flared up in 2025. The question arises: Why are both Phnom Penh and Bangkok not truly willing to de-escalate? What are the political and geostrategic motives behind this?

2. History of the Dispute: From Colonial Legacy to Political Tool

The Preah Vihear dispute originated from a map drawn by the French in the early 20th century. In 1962, the International Court of Justice (ICJ) ruled that the temple belonged to Cambodia, but the surrounding land area remains ambiguous regarding sovereignty. This issue has become a “potential powder keg,” utilized by the governments of both sides to consolidate their position whenever public support is needed.

In Thailand, the military and royalist factions often emphasize a hardline stance, while civilian governments sometimes seek reconciliation but are accused of “selling out the country.” In Cambodia, former Prime Minister Hun Sen previously leveraged this issue as a tool to rally public support, and now his successor, Hun Manet, faces pressure to demonstrate similar fortitude.

3. Internal Political Motives: The “Useful Fuse”

Thailand

• Protracted Political Crisis: Thailand has been mired in years of instability between the “Red Shirts” and “Yellow Shirts,” and between military forces and civilian factions. The current government is under immense pressure from various political groups, especially after former Prime Minister Thaksin Shinawatra, following his reappearance, withdrew from an advisory role. This power vacuum compels many groups in the political arena to find a new “rallying tool,” and border tensions have become a familiar choice.
• Pressure from the Military: The Thai military maintains significant influence in politics, often using security issues to solidify its role. A border confrontation, even if controlled, can help the military prove its necessity in political life.

Cambodia

• Hun Manet and the Pressure of Succession: New Prime Minister Hun Manet, who succeeded his father Hun Sen, still needs to affirm his position. Any sign of “softness” toward Thailand could be criticized as “unworthy” of his father’s political legacy. Therefore, a hardline stance becomes a necessary choice.
• Legitimacy and Public Sentiment: Territorial sovereignty is always a sensitive topic. The Phnom Penh government understands that “yielding” could provoke a fierce reaction from a populace proud of the 1962 ICJ victory.

4. The Role of Great Powers: China, the US, and ASEAN

China – Phnom Penh’s “Diplomatic Shield”

Cambodia is one of China’s closest allies in Southeast Asia. Beijing has invested tens of billions of dollars in infrastructure, Special Economic Zones, and energy projects in Cambodia. Furthermore, Cambodia has repeatedly sided with China on the South China Sea issue within ASEAN, demonstrating a close relationship.

Amid border tensions, Beijing has a motive to “back” Phnom Penh with political support and economic aid, thereby keeping Cambodia within its orbit of influence. Although China denies providing new weaponry, past military support (training, equipment) makes Cambodia somewhat more confident in confronting Thailand.

The US – Limited but Symbolic Presence

The United States closely monitors the situation, but its actual involvement is relatively limited. Washington primarily emphasizes the message of “maintaining stability, preventing ASEAN division.” However, the US still holds some influence over the Thai military through the annual Cobra Gold exercise. In the eyes of some analysts, this is a “soft leverage” for Washington to restrain Thailand from going too far in the tensions.

ASEAN – The Weak Voice

Despite having a mediation mechanism, ASEAN is often helpless in the face of bilateral sovereignty disputes. The Cambodia-Thailand case is further complicated by diverging interests within the bloc. This is why the mediating role of Vietnam (to be discussed later) is considered more crucial than ASEAN generally.

5. Vietnam: Interests and the Role of “Balance Keeper”

Vietnam has several interests in maintaining peace between Cambodia and Thailand:

• Stability of the Southwestern Border: Instability in Cambodia could spill over into Vietnam through trade routes, labor migration, and religious issues.
• Protecting ASEAN Unity: Vietnam always wants a stable ASEAN to act as a counterweight to external great powers.
• Preventing Deep Chinese Interference: If Cambodia becomes overly dependent on China, the strategic balance in the region would unfavorably tilt against Vietnam.
• Economy and Trade: Vietnam has significant interests in cross-border infrastructure connectivity with Cambodia and Thailand, especially the East-West Economic Corridor.

Therefore, Hanoi can play the role of a “soft intermediary,” through bilateral diplomatic channels and the ASEAN mechanism, to promote dialogue and limit the risk of escalating conflict.

6. Social Reaction: What Do the People Think?

• In Cambodia: National sentiment is very strong. Many citizens view Preah Vihear as a sacred symbol and are willing to support the government in maintaining a hardline stance. However, in border areas, people are weary of having to evacuate and lose their livelihoods every time tensions flare up.
• In Thailand: The public is divided. A segment of nationalists supports strong action, while the business community and urban middle class worry that conflict would affect the economy, investment, and tourism.

7. Weaponry and Military Capabilities

There is currently no clear evidence of Cambodia or Thailand receiving significant new weapon shipments in 2025. However:

• Cambodia has received military aid from China for many years, including armored vehicles, radar systems, and officer training.
• Thailand has a stronger military, supplied with equipment by the US and some European countries. Thailand’s air force and artillery capabilities are considered superior.

Consequently, if a full-scale conflict were to erupt, the balance of power would tilt toward Thailand. However, Cambodia could rely on China’s “diplomatic shield” to restrict Thailand’s escalation.

8. Three Future Scenarios

• Scenario 1: Controlled Tension (Highest probability, ~60%) The two sides continue to maintain tensions at the level of a “border hotspot” but do not escalate into full-scale war. Bilateral negotiations, with support from ASEAN and Vietnam, help maintain a state of “neither peace nor war.”
• Scenario 2: Military Escalation (Medium probability, ~30%) A clash causing significant casualties or a political incident (like a Thai government crisis) could cause the conflict to escalate. However, international pressure, especially from the US and China, would quickly force both sides to de-escalate.
• Scenario 3: Long-term Reconciliation (Low probability, ~10%) Both sides agree to return the dispute to the ICJ or establish a joint management mechanism for the border area. This is the ideal scenario but is difficult to achieve due to the lingering strength of internal political motives.

9. Conclusion: Border Dispute – A Tool or a Risk?

The current Cambodia-Thailand tension reflects a paradox: neither government wants war, but neither wants to de-escalate due to internal political motives. In this context, China and the US each have their own influence, while Vietnam emerges as an important factor in maintaining regional balance.

The future will depend on two factors:

• Internal political developments in Bangkok and Phnom Penh (especially after the withdrawal of Thaksin).
• The degree of great power involvement, particularly China.

What is certain is that, regardless of the developments, the people living along the border will continue to suffer the most. Therefore, the responsibility of both governments is to find a way to manage the dispute humanely and wisely, rather than letting it become a “political flame” serving short-term interests.