Despite months of behind-the-scenes negotiations and the personal involvement of Secretary of State Alexander M. Haig Jr., prospects for a united front of Cambodia's major anti-Vietnamese resistance groups are slim.
Former Khmer Rouge leader Pol Pot, former Premier Son Sann, and exiled Prince Norodom Sihanouk have recently conducted a series of discussions, privately and through the press, aimed at forging an alliance. They have been prodded by Thailand and its partners in the Association of Southeast Asian Nations (ASEAN), by China, and by the US.
But the suspicion and hostility among Son Sann's Khmer People's National Liberation Front (KPNLF), the Khmer Rouge, and Sihanouk's forces have not been overcome. And differences have begun to emerge between Washington, Bangkok, and Peking on how to structure and support a united front.
This little-publicized development makes it even less likely that an alliance can be created before next month's United Nations conference on Cambodia or this fall's UN general Assembly session. Those opposed to the Vietnamese presence in Cambodia have been counting on the formation of such an alliance to maintain the diplomatic pressure on Hanoi.
The key question is in what form, and under what leadership, the Khmer Rouge, with its gruesome record of mass murders during its rule of Cambodia, should participate.
With about 30,000 soldiers and proven experience in guerrilla war, the Khmer Rouge are the largest and strongest of the anti-Vietnamese organizations. By contrast, Son Sann is believed to have no more than 3,000 to 5,000 poorly equipped men, while Sihanouk has perhaps half as many.
Son Sann is untainted by the bloody past of the Khmer Rouge, and Sihanouk as well has a relatively good reputation. This means they can offer what the Pol Pot forces badly need -- respectability to boost their flagging support and help maintain their hold on Cambodia's UN seat.
But precisely because his "clean" image is his chief political asset, Son Sann has been unwilling to join a united front without substantial concessions from the Khmer Rouge.
Son Sann has insisted that the most notorious of the Khmer Rouge leaders -- Pol Pot, Ieng Sary, and several others -- go into exile in China. He has also demanded the KPNLF be given most of the portfolios in any coalition government, and that China or the US provide his army with enough military aid to defend itself against any Khmer rouge treachery.
But the Pol Pot forces, while willing to compromise on allowing the KPNLF into a provisional government, have rejected proposals for top Khmer Rouge figures to leave the political stage, claiming such a step would undercut their ability to fight in the Vietnamese.
Meanwhile, from his homes in North Korea, Peking, and France, Prince Sihanouk has been changing his position with such breathtaking frequency that nobody knows under what circumstances he would be willing to join a coalition. Moreover, the prince's relations with Son Sann are still strained, primarily because of lingering bitterness over political disputes dating back to the 1960 s.
According to well-placed diplomatic sources, Thailand and China are basically committed to the Khmer Rouge, as the only viable anti-Vietnamese resistance.
In sharp contrast, the sources report that the Reagan administration has told the Thais and the Chinese it is does not support the Khmer Rouge. Instead, Washington is said to have proposed that Son Sann and other noncommunist forces be given more political, economic, and military support, both to give the resistance greater international credibility and also reduce the chances of the Khmer Rouge ever returning topower.
The sources said this question was high on Secretary Haig's agenda during his just-concluded trip to Peking. Mr. Haig reportedly urged the Chinese, Pol Pot's primary supporters, to accept significant changes in the Khmer Rouge leadership. And the secretary of state is also said to have asked Peking for weapons for Son Sann.