Three of Harvard's leading East Asia experts reacted skeptically yesterday to President Nixon's pledge last week to end the Cambodian bombing on August 15.

John K. Fairbank, professor of History, said last night that Nixon "has always gotten around" previous promises to reduce military actions in Southeast Asia and that he had "no idea" whether the bombing would end on schedule in mid-August.

Both Alexander B. Woodside, assistant professor of History, and James C. Thomson, curator of the Nieman Fellowships, yesterday echoed Fairbank's unsure assessment of the prospects for peace in Cambodia.

Woodside, a Southeast Asian expert, said peace will hinge on whether the Nixon Administration accepts the need to deal with Prince Norodom Sihanouk, who was deposed in 1970 by the present Lon No1 government.

Woodside said he doubted whether the Lon No1 government would survive even with continued American bombing. He explained that Sihanouk appears to be the only person with ties to both the Khmer Rouge Cambodian revolutionary movement and the international community-- connections upon which a stable peace must necessarily be founded.

Thomson, who specializes in East Asian-American relations, agreed with Woodside's assessment of Sihanouk's importance. "The only guy who can pull a Cambodian government together is Sihanouk," he said.

The White House announced last week that negotiations are underway at present with what it calls the 'insurgent forces,' evidently meaning Sihanouk and the Khmer Rouge. Sihanouk has denied that any talks are taking place.

All three specialists said they had no information as to whether any diplomatic contacts were being made. "They don't always talk about these things while they are going on, but I have no idea whether any negotiations are taking place," Fairbank said.

Thomson speculated that the United States "may try rather desperately to get a face-saving agreement" by attempting to enlist the aid of the People's Republic of China and the Soviet Union.

Woodside and Thomson agreed that the Lon Nol government will eventually fall, giving way in all likelihood to a left-wing government headed by Sihanouk that will adopt an independent stance in foreign affairs.

"A Communist or Communist-leaning government will eventually come to power," Thomson predicted.

Both men disputed the Nixon assertion that the Khmer Rouge are led by North Vietnamese. "The Khmer Rouge are Asian Communists who were well-trained by their more disciplined neighbors, the Vietnamese," Thomson said. "But they are Cambodian--and they would never accept control from outside their country."

Woodside explained that much of Cambodian history has been a continual effort to fend off Thai encroachments from the west and Vietnamese advances from the east. "Historically, any Cambodian politician who received Vietnamese aid would eventually be a dead duck in Cambodian politics," he said.

Thomson agreed that Cambodia has been the cockpit of conflict in Southeast Asia. "Cambodia is the Poland of the area," he said.

Woodside explained that the Khmer Rouge appear to be particularly strong in western Cambodia, the only area of the country that has big landed estates. "They also have European-educated urban intellectuals working for them," he said.

The American bombing, Woodside added, has added to the rural support for the Khmer Rouge