Thai Coalition Collapse: Bhumjaithai Party Exits, Heightening Border Tensions with Cambodia

Thailand's political landscape faced a significant upheaval on June 18, 2025, as the Bhumjaithai Party, the second-largest faction in the ruling coalition, announced its withdrawal from Prime Minister Paetongtarn Shinawatra's government. The party's departure, effective June 19, leaves the coalition with a fragile majority, raising concerns about the administration's stability amid escalating border tensions with Cambodia.

The catalyst for Bhumjaithai's exit was a leaked phone conversation between Prime Minister Paetongtarn and former Cambodian Prime Minister Hun Sen. In the recording, Paetongtarn reportedly criticized Lieutenant General Boonsin Padklang, the commander overseeing the Cambodian border. This critique prompted Bhumjaithai to question the Prime Minister's handling of the border situation, emphasizing their support for the military and national integrity. The party stated that all its ministers had submitted their resignations, effective June 19.

The Bhumjaithai Party, established in 2008, has been a significant player in Thai politics, often acting as a coalition partner in various governments. Its withdrawal reduces the ruling coalition's majority, making it vulnerable to no-confidence motions and legislative gridlock. This political instability comes at a time when Thailand is grappling with economic challenges, including potential U.S. tariffs and declining foreign investment.

The leaked conversation has intensified scrutiny over Prime Minister Paetongtarn's leadership. As the daughter of former Prime Minister Thaksin Shinawatra, Paetongtarn became Thailand's youngest prime minister in August 2024. Her tenure has been marked by efforts to navigate complex political landscapes and address economic challenges. The current crisis tests her ability to maintain coalition unity and manage diplomatic relations with neighboring Cambodia.

The border tensions between Thailand and Cambodia have been escalating since a deadly clash on May 28, 2025, in the disputed Emerald Triangle region. The skirmish resulted in the death of a Cambodian soldier and has led to retaliatory actions from both nations, including military buildups, cross-border embargoes, and media bans. Cambodia has referred the dispute to the International Court of Justice (ICJ), a move Thailand rejects, preferring bilateral negotiations.

The political fallout from Bhumjaithai's withdrawal may embolden Cambodia in the ongoing border dispute, potentially escalating military confrontations. Additionally, the government's ability to address economic challenges may be compromised, as political instability can deter foreign investment and tourism, sectors crucial to Thailand's economy.

In response to the crisis, Lieutenant General Boonsin Padklang stated, "I informed the prime minister that I had no issue with her and that I understood her." This comment suggests an attempt to de-escalate internal tensions within the military and government.

Historically, Thailand has experienced coalition breakdowns leading to political instability and changes in leadership. However, the current situation is unique due to the interplay of internal political dynamics and external border tensions. Bhumjaithai's withdrawal may be influenced by a desire to distance itself from a potentially unpopular government amid rising nationalist sentiments. Aligning with the military and emphasizing national integrity could bolster the party's standing among conservative constituents.

As Thailand navigates this complex political and diplomatic landscape, the coming days will be crucial in determining the stability of the government and the direction of its foreign relations. The situation underscores the delicate balance between domestic politics and international diplomacy in Southeast Asia.