More than 500,000 people have fled the Thailand-Cambodia border as fighting escalates over a decades-old territorial dispute involving ancient temples. Hostilities resumed despite a ceasefire brokered by US President Donald Trump in October after his tariff threats ended clashes in July. Trump now vows to intervene again, but Thailand rejects outside mediation. With tensions high and previous truce efforts failing, it is unclear what leverage the United States can use to stop the conflict.