Thailand’s military conflict with Cambodia is inflaming nationalist tensions at home and threatening embattled leader Paetongtarn Shinawatra, who had already been suspended as prime minister for her handling of the border dispute.

Hours after Thai fighter jets struck Cambodian military positions and Phnom Penh hit civilian areas in the deadliest clashes in over a decade, Thai nationalist groups announced plans for an anti-government rally in Bangkok on July 27. Tweets supporting the Thai army and air force were trending on social media platforms X and Facebook in Thailand.

Ms Paetongtarn is already in a precarious position over her handling of the border issue, thanks to the

with former Cambodian leader Hun Sen in which the 38-year-old was sympathetic to her neighbour and critical of the powerful Thai military. That led to complaints to the Constitutional Court, which suspended her as prime minister.

“Heightened military tensions reaffirm expectations that the Constitutional Court will likely rule that Paetongtarn be removed from office,” said Mr Peter Mumford, South-east Asia practice head at Eurasia Group.

“If snap elections take place in Thailand later this year or next year, conservative parties will hope to ride a wave of nationalist sentiment, with populist Pheu Thai on the backfoot,” he added.

Thailand’s Pheu Thai-led coalition has been on the brink after the defection of a key party in June left it with a slender majority.

Ms Paetongtarn herself took power only after a court removed her predecessor, while her father Thaksin Shinawatra was ousted in a 2006 coup.

“The continuation of this government has gravely undermined and endangered the country’s security in all dimensions – including national honour, national interests and public assets – and has resulted in a complete loss of trust and public order,” protest leader Pichit Chaimongkol said at a briefing on July 24.

Thai-Cambodian tensions have been running high since a May

, and the countries have disputed their roughly 800km border for decades. The Thai army on July 25 asked people to stay away from border areas, saying fighting continues.

In 2003, the Thai Embassy in Phnom Penh was destroyed in riots by Cambodians angered by a Thai celebrity who suggested that the iconic Angkor Wat temple complex was Thai, while clashes from 2008 to 2011 killed more than two dozen people on both sides of the border.

Much of the argument stems from different maps based on the text of Franco-Siamese treaties of the early 1900s that laid out boundaries between Thailand and Cambodia, which was then part of French Indochina.

The latest crisis comes at a challenging time for both countries, with the US threatening to impose stiff tariffs from Aug 1. While neighbouring Indonesia, the Philippines and Vietnam have secured trade agreements with the Trump administration, export-dependent Thailand does not yet have a deal.

The July 24 fighting killed at least 14 people and injured dozens in Thailand, which launched air strikes against at least three Cambodian military bases. The Thai army has been allowed a relatively free hand in conducting its operations.

The government’s actions on the Cambodia issue risk lending more legitimacy to the military and boosting its popularity in Thai politics, said Dr Titipol Phakdeewanich, a political science lecturer at Ubon Ratchathani University.

“Pheu Thai’s inability to lead the government effectively is leading to popularity for the military,” he said.

Thai politics has been dominated by a longstanding power struggle between populist, pro-democracy forces and a pro-military establishment made up of wealthy elites and royalist bureaucrats.

Since the end of absolute monarchy in 1932, the nation has seen roughly a dozen coups and about 20 constitutions. At least four governments backed by the influential Shinawatra clan have been dismissed, either through coups or court orders.

Ms Paetongtarn and Mr Thaksin, who is the de facto leader of Pheu Thai, have both expressed support for the Thai military.

Still, during his long, post-coup exile from Thailand, Mr Thaksin was named an economic adviser to then Cambodian Prime Minister Hun Sen, angering the military-backed authorities in Bangkok at the time.

Their relationship has since deteriorated, with Mr Thaksin taking to X to criticise the former Cambodian leader, whose son is the current prime minister.

While countries have offered to mediate in the conflict, “we probably need to let the Thai military do its job and teach Hun Sen a lesson about his cunning ways first”, Mr Thaksin said.

“I am not surprised by Thaksin’s attitude towards me,” Mr Hun Sen tweeted in turn, criticising his “war-like” tone and accusing him of multiple betrayals.

He also mentioned a mass killing of Thai Muslims that occurred during Mr Thaksin’s premiership in 2004, which was widely condemned by human rights groups.

Ms Paetongtarn, who attends Cabinet as the culture minister, is facing a Thai Constitutional Court probe of alleged ethical violations in her handling of the border dispute. She has until July 31 to submit her defence.

Mr Mumford said: “The border skirmish will strengthen (the) conservatives and there will be speculation that, alongside domestic political developments, it could trigger a military coup – though this does not currently seem on the cards.

“The odds of a coup will rise if the security and political environment worsens further.” BLOOMBERG