A panel of experts – including a would-be US assistant secretary of defence, analysts and the daughter of jailed opposition head Kem Sokha – convened on Tuesday night in the US capital and called on America and other world powers to impose sanctions.

Randy Schriver, recently nominated Assistant US Secretary of Defense for Asian and Pacific Affairs, stressed the importance of Cambodia for American interests, saying that losing influence in the Kingdom would allow China to otherwise win “regional competition”.

And John Sifton, Human Rights Watch’s Asia advocacy director, said the arrest of Sokha in early September had led to the “complete breakdown” of the Cambodia-US relationship, leaving the government with limited diplomatic influence. Nevertheless, the US could use its relationships with Japan and the European Union to exercise pressure.

Kem Monovithya, one of Sokha’s daughters and CNRP deputy director-general of public affairs, said the international community would be responsible for democracy’s disappearance if it does not act with sanctions before the end of the month.

“You all will become accomplices in the destruction of Cambodian democracy,” she said. “The right strategy would be to pre-empt – not to anticipate what the Cambodian government is going to do next . . . We are an inch away from big positive change. One last little stretch and we get there,” she said.

Olivia Enos, a policy analyst at the Heritage Foundation – a conservative think tank that hosted the panel – suggested a mix of short- and long-term strategies.

She suggested the US impose individual sanctions on senior government officials, either under the Global Magnitsky Act – which allows the executive branch to impose targeted sanctions on individuals for human rights or corruption violations – or the Specially Designated National (SDN) list, a Treasury Department classification under which assets are frozen and business dealings restricted.

Political commentator Ou Virak said yesterday that putting officials on a SDN list would be the most likely response from the US government.

“SDN is a big deal as it would also target family members of officials listed and it puts an embargo on US companies, citizens and permanent residents from doing business with these officials,” he said, adding he expects visa restrictions imposed on certain officials and their families.

“I don’t expect the SDNs will be implemented for a while . . . I think by then the situation here will start to be calm again,” he said, estimating this would take place in four to five months when the CNRP would be sufficiently weakened for the purposes of the CPP.

Meanwhile, Monovithya called on the EU and Japan, the two biggest donors supporting elections, to not only withdraw technical support for the elections if the crackdown continued, but to attack the legitimacy and credibility of the government.

But Human Rights Watch’s Sifton said they should move away from discussing “how to put pressure on Cambodia”, and on to how to isolate Prime Minister Hun Sen as an individual – including within his own party.

States should focus on “isolating him as pariah, isolating him economically”. This could take place in the form of sanctioning him individually, or targeting senior government officials while leaving him alone, for example by freezing assets.

Australia and Singapore, for instance, could use their anti-corruption laws to do so, he said.

He added that during the upcoming Asean summit in Manila in mid-November, Trump himself could tell the premier that if the CNRP is dissolved the US would no longer recognise him as a democratic leader.

CPP spokesperson Sok Eysan, however, said he didn’t expect sanctions from the US. “No need to worry, there won’t be anyone putting sanctions on us,” he said. “The US government, like Donald Trump, has changed its mind not to interfere in Cambodian internal affairs.”

Eysan added that NGO representatives are “useless people”, and referred to Human Rights Watch’s Asia director, Brad Adams, as “Hell Adams”, alluding to a similar sounding word in Khmer.

Additional reporting by Ben Sokhean