PHNOM PENH, CAMBODIA -- To his opponents, Prime Minister Hun Sen is a "traitor" and a "puppet," a former Khmer Rouge guerrilla who collaborated with the Vietnamese troops who invaded and occupied Cambodia. To his growing number of supporters inside Cambodia and abroad, he is a patriot, committed to regaining his country's independence, unifying the four warring factions and improving the living standards of the rural peasantry. Whichever view history bears out, Cambodia's 38-year-old Hun Sen has emerged from the obscurity of his peasant-fighter background to become one of the two central figures who will determine the fate of Cambodia and its 8 million people. The other is Prince Norodom Sihanouk, former ruler of Cambodia, who has headed a tripartite guerrilla coalition fighting Hun Sen's Vietnamese-backed government. According to many analysts, Sihanouk and Hun Sen must find a political accommodation before Cambodia can end its long civil war. In recent months, Hun Sen has become the most visible and articulate salesman -- in the international arena and within his own ruling Communist Party Politburo -- for the economic and political revisions Phnom Penh is moving to adopt. He has increased his profile in the countryside, and frequently discusses key issues on state-run radio. For example, after his last meeting with Sihanouk in May, he went on the radio to explain the peace process. He has also been presiding at religious ceremonies, and was televised praying with leading Buddhist monks in January when a sacred relic -- said to be a bone of Buddha -- was returned to a blue temple in front of the Phnom Penh train station. Hun Sen travels to Cambodia's provincial villages two or three times a month "to listen to the people and to explain to the people the positions of the party," said Cham Prisit, a close adviser. On these trips, he and others said, Hun Sen often borrows a motorcycle and rides to isolated hamlets with the fervor of a Western-style politician. Said one foreign relief worker, "He's really into the hard-sell style of politics -- almost to the point of kissing babies." "Everybody knows Hun Sen," said a foreign relief worker here. "I think people are really responding to the propaganda effort. Young people especially identify with Hun Sen." Several Cambodian officials, foreign diplomats and relief workers interviewed here said they believed that Hun Sen has become so popular within Cambodia that he now rivals Sihanouk, setting the stage for what some foreign residents said could be a fascinating electoral showdown if elections are held. "Sihanouk has always enjoyed the support of the peasants, but never the intellectuals," said Khieu Kanharit, editor of the weekly newspaper Kampuchean and a party member. "Hun Sen is supported by both." Diplomats and other regional analysts said Hun Sen's international stature has grown considerably since his visit earlier this year to Bangkok, where Prime Minister Chatichai Choonhavan gave him a reception fit for a head of government, including a lavish dinner. While his government is still only recognized by the East Bloc countries and India, Hun Sen emerged from his Bangkok visit -- as well as from his talks with Sihanouk -- as a key player in the Cambodian imbroglio and no longer just a client of Vietnam, these diplomats and others said. Hun Sen appears publicly to have all but eclipsed his nominal superior, Communist Party General Secretary and Cambodian President Heng Samrin, whose official portrait still graces the walls of most government buildings in Phnom Penh and in the provincial capitals. Where once foreign diplomats spoke of "the Heng Samrin regime," they now refer to "the Hun Sen government." But despite his increased visibility, some foreign analysts and Cambodian officials said they believe that within the ruling government and party circle, Hun Sen is by no means the most powerful player. Decisions are still believed to be made by a consensus of the party leadership, which is balanced between reformists and the older, hard-line ideologues. Hun Sen, they said, must always be careful not to overstep his rank -- he is only number three in the Politburo hierarchy, behind Heng Samrin and National Assembly chairman Chea Sim -- and must honor Asian tradition by showing the proper respect for his elder colleagues. "Hun Sen may be personalizing Cambodia for the outside world, but certainly he is not the man who makes all the decisions," said a Soviet diplomat in Phnom Penh, who asked not to be quoted by name. "There is no such man . . . . The decision-making process is a collective effort." Chea Sim is believed to exercise considerable influence in the party. He also has been taking a higher public profile, traveling to villages and appearing at well-publicized ceremonial functions. And despite his relatively low public posture, Heng Samrin, who has close ties with the leadership in Vietnam, is believed to wield considerable influence. Relatively little is known about Hun Sen's early life. According to his official biography, he was born in April 1951, in Kompong Cham Province, the son of peasant farmers. He joined the Khmer Rouge as a guerrilla when he was 17, fighting mainly in Cambodia's Eastern Zone, the military area that borders Vietnam. His official biography says he rose to the rank of division commander in the guerrilla army and was wounded five times. He also lost his left eye. The biography says Hun Sen defected from the Khmer Rouge on June 20, 1977, after "having witnessed the barbarous policy of genocide carried out" after the Khmer Rouge came to power in April 1975. It says Hun Sen led an unspecified number of "cadres and soldiers" to form a new armed force to oppose the Khmer Rouge, which killed between 1 million and 2 million Cambodians during their nearly four-year rule of the country.