A fragile peace brokered by U.S. President Donald Trump has collapsed as Thailand and Cambodia plunged back into armed conflict on Monday. The Thai military confirmed it carried out airstrikes on Cambodian territory after Cambodian troops allegedly opened fire in Ubon Ratchathani province at dawn, killing one Thai soldier and wounding four others. In response, Thailand deployed aircraft to strike several Cambodian military targets. Phnom Penh countered that Thai forces initiated the violence, shelling areas near the historic Preah Vihear and Ta Moan Thom temples with tanks and artillery in Oddar Meanchey province. Heavy exchanges have forced the evacuation of entire border villages; Thai authorities report relocating more than 35,000 civilians. The flare-up follows months of calm after a deadly five-day clash earlier this year that left at least 43 dead and displaced nearly 300,000 people. The ceasefire signed under Trump’s mediation in October was unilaterally suspended by Thailand last month, citing landmine injuries to its troops. With both sides blaming each other for the first shot, fears are growing of a wider regional conflict reigniting over the long-disputed border zone.