In an interview on Sunday from Paris, where he has lived in exile since November 2015, Mr. Sam Rainsy. a French-educated former banker, said he had quit as a “pre-emptive defensive move” to save his political party.
This month, Mr. Hun Sen proposed a measure that could dissolve any party led by someone convicted of a crime, which Mr. Sam Rainsy has been many times, because of an abundance of criminal defamation suits filed against him by government officials, government allies and the prime minister himself.
“This guy is crazy,” Mr. Sam Rainsy said of Mr. Hun Sen. “He can do anything he wants without consideration for legal, judicial principles, so I have to defend my party and tell Hun Sen and tell the Cambodian people and tell the whole world that Hun Sen no longer has any grounds to dissolve the C.N.R.P. on the basis that his kangaroo court has made me a convict.”
He was vague about his political future.
“In politics, there are always ups and downs,” he said. “Things can change.”
Ou Virak, the chairman of the Future Forum, a public policy research group in Phnom Penh, the capital, said the departure of Mr. Sam Rainsy was a blow for Cambodia’s fledgling democracy.
“Leaving in this kind of situation, when the party is under pressure, is not ideal or democratic,” he said. “It highlights the nature of Cambodian politics for the past 20 or so years. Politics is not created by competition and ideas, but personalities and maneuvering to get what people want.”
Mr. Sam Rainsy was one of those personalities. Despite his weaknesses, including a tendency to flee the country in the face of trouble, he is still, for many, the most enduring symbol of opposition to Mr. Hun Sen. The prime minister, a former Khmer Rouge fighter, has held power since 1985 and maintains close control over almost all of the country’s institutions.
“Rainsy is a character with a lot of flaws, but it has to be recognized that he has maintained this position of opposition for nearly a quarter-century,” said Sebastian Strangio, the author of the book “Hun Sen’s Cambodia.” “At any time, he could have sold out to the C.P.P. and become a rich man,” he said, referring to the Cambodian People’s Party, led by Mr. Hun Sen.
Mr. Sam Rainsy, while clearly irritating the prime minister, proved useful over the years by presenting an internationally visible opposition figure to run in elections, which Mr. Hun Sen always won, Mr. Strangio added.
But Mr. Sam Rainsy began to pose a more existential threat to Mr. Hun Sen’s political survival when he formed a partnership with another government critic, Kem Sokha, in 2012. Their new political party nearly won the 2013 national election, emboldening them and stunning the C.P.P.
Mr. Hun Sen and Mr. Sam Rainsy came to a brief rapprochement in 2014 and 2015, with the opposition leader extracting some important political concessions from Mr. Hun Sen, including equal representation on the National Election Committee and a television broadcasting license.
But a few months later, the friendly feelings dissolved, and many of the concessions were rescinded.
It has been hard to keep up with the number of lawsuits filed against Mr. Sam Rainsy and other opposition figures over the last 18 months, many involving allegations of criminal defamation against government officials.
Salacious telephone conversations involving Mr. Kem Sokha and other opposition lawmakers have also been leaked online and discussed widely in government-friendly news media. The most recent recording, released a week ago, involved a man who sounded like Mr. Sam Rainsy bantering with a waitress about her eating and bathing habits.
Mr. Sam Rainsy’s moral authority was also being eroded from within his party. While he fled the country in November 2015 to avoid jail time, Mr. Kem Sokha made a point of staying after being charged with crimes related to a suspected affair. Eventually, the government pardoned him.
Mr. Kem Sokha is now set to become the acting opposition leader. In a statement on Sunday, he called Mr. Sam Rainsy’s decision honorable and said it had been made in discussion with the party’s leadership.
Phay Siphan, a government spokesman, said the many lawsuits against opposition figures were private matters, and he accused Mr. Sam Rainsy of trying to generate publicity with a dramatic exit.
“He is an opportunist,” Mr. Phay Siphan said. “Tell me, so far, in the last 20 years, what has he done for Cambodia except move the people to go on strike and have demonstrations?”
Mr. Phay Siphan also criticized the United States representatives Alan Lowenthal and Steve Chabot, members of a new congressional caucus on Cambodia, for writing to Secretary of State Rex W. Tillerson on Feb. 9 about the need to promote free and fair elections in Cambodia.
Mr. Phay Siphan called the representatives “blind” and “ignorant,” and he suggested that Mr. Sam Rainsy was taking cues from them.
Mr. Sam Rainsy countered that all he wanted was for his party to survive long enough to run in the elections, with or without him.
“It is Hun Sen who sees me behind any initiative to defend democracy,” he said, “but I think Cambodia has many sons, many daughters, who are willing to defend democracy.”
Continue reading the main story