Hun Sen, Cambodia's tough and wily prime minister, marked 30 years in power Wednesday, one of only a handful of political strongmen worldwide who have managed to cling to their posts for three decades.

Since first taking up the job of prime minister at age 33, he has consolidated power with violence and intimidation of opponents that continue to draw criticism from human rights advocates. But he could also take some credit for bringing modest economic growth and stability in a country devastated by the communist Khmer Rouge's regime in the 1970s, which Hun Sen had abandoned as they left some 1.7 million people dead from starvation, disease and executions.

In a speech inaugurating the country's longest, 2,200 meter (7,200 foot) bridge across the Mekong River on Wednesday, Hun Sen, 62, defended his record, saying that only he was daring enough to tackle the Khmer Rouge and help bring peace to Cambodia.

"If Hun Sen hadn't been willing to enter the tigers' den, how could we have caught the tigers?" he said. He acknowledged some shortcomings, but pleaded for observers to see the good as well as the bad in his leadership.

Born to a peasant family in east-central Cambodia, Hun Sen initially joined the Khmer Rouge against a pro-American government. He defected to Vietnam in 1977, and accompanied the Vietnamese invasion that toppled his former comrades in 1979.

The timely change of sides led to his being appointed foreign minister, then prime minister of the Vietnamese-supported regime in 1985. Since then, he has never left the top post despite being forced to temporarily accept the title of "co-prime minister" after his party came in second in a 1993 U.N.-supervised election. Four years later, he deposed his coalition partner in a bloody coup.

"It is superficially true that relative peace and stability occurred during the reign of Hun Sen's three decades in power. But Hun Sen's 'achievements' are only relative to the blackness of the Khmer Rouge," said Theary Seng, a Cambodian-American lawyer and human rights activist.

Historian David Chandler, a Cambodia expert at Australia's Monash University, has characterized Hun Sen as "intelligent, combative, tactical, and self-absorbed."

According to the New York-based group Human Rights Watch, Hun Sen has been linked to a wide range of serious human rights violations: extrajudicial killings, torture, arbitrary arrests, summary trials, censorship, bans on assembly and association, and a national network of spies and informers intended to frighten and intimidate the public into submission."

In 2013 elections, it seemed Hun Sen's grip on power had been shaken when the opposition Cambodia National Rescue Party mounted an unexpectedly strong challenge, winning 55 seats in the National Assembly and leaving Hun Sen's Cambodian People's Party with 68.

The opposition alleged the results were rigged and its lawmakers at first boycotted the legislature. But then, Hun Sen brokered a deal with opposition leader Sam Rainsy and the parliament resumed work, with the longtime leader again appearing unscathed.

Human Rights Watch said in Wednesday's report that "Cambodia is in the process of reverting to a one-party state."

"After 30 years of experience, there is no reason to believe that Hun Sen will wake up one day and decide to govern Cambodia in a more open, inclusive, tolerant, and rights-respecting manner," said the Asia director at Human Rights Watch, Brad Adams, who authored the report. "The international community should begin listening to those Cambodians who have increasingly demanded the protection and promotion of their basic human rights."