When weeks of tensions escalated into a major border conflict with Thailand last week, former Cambodian Prime Minister Hun Sen appeared to take charge of his country's response.

Photographs showed him at the end of a long table, speaking with military officers and poring over detailed maps, radio set in hand and a cup of Starbucks coffee within arms reach. The former guerrilla fighter is no longer Cambodia's leader, having passed on the premiership to his eldest son in 2023 after nearly four decades in power, and has taken over as the president of the Southeast Asian nation's Senate.

But Hun Sen played an outsize role in events leading up to the deadliest fighting between Thailand and Cambodia in over a decade and — according to three diplomatic sources — showed his continuing influence during the five-day conflict. On Friday, after artillery fired from Cambodia landed in civilian areas in Thailand's border provinces, the Thai army took direct aim at him.