China and the noncommunist nations of Southeast Asia may be splitting further apart over Vietnam. Indeed, one result of Thai Prime Minister Prem Tinsulanonda's current trip to China may well be less cooperation between China and the Association of Southeast Asian Nations (ASEAN) on how to deal with Vietnam's military occupation of Cambodia.
General Prem had gone to Peking, partly at least, to urge China to shift support from the Khmer Rouge and accept an alternative to both the Khmer Rouge and the Vietnamese-dominated Heng Samrin government in Phnom Penh.
Thailand, like other members of ASEAN (Malaysia, Singapore, Indonesia, and the Philippines), is acutely aware that supporting the Khmer Rouge as Cambodia's representative at the United Nations puts Thailand in an increasingly embarrassing position. Under Pol Pot the Khmer Rouge regime became synonymous with brutality.
ASEAN officials are concerned that their apparent support for Khmer Rouge guerrillas puts them on a dead-end diplomatic path unless they shift course before next year's UN General Assembly.
There is a strong feeling they must find a new approach despite ASEAN's victories at the General Assembly this year. So far the noncommunist Asian bloc has been able to retain the Cambodian seat for the Khmer Rouge. Last week ASEAN scored another success with General Assembly endorsement of its call for a Vietnamese military withdrawal from Cambodia, an international conference on the problem, and UN-supervised free elections.
So far, Vietnam has denounced the idea of an international conference on Cambodia. Elections to be conducted with no outside supervision by the Heng Samrin government are sufficient, it maintains.
All this is especially tricky for Thailand. Unlike other ASEAN countries, it needs China's pledge to attack Vietnam if Vietnamese troops in Cambodia attack Thailand. Also if Thai-Chinese relations deteriorate, China could step up support for communist guerrillas in Thailand. Publicly, at least, some ASEAN officials express hope China will go along with a new approach, particularly since Singaporean diplomats claim to have evidence China is backing off from the Khmer Rouge.
But some Western diplomats express skepticism. They say there is no evidence that China is abandoning its long-term policy of "bleeding" Vietnam by supporting the Khmer Rouge as the only effective anti-Vietnam fighting force in Cambodia.
The assessment of Prime Minister Prem's recent China talks will give further clues.
Peking Radio's description of General Prem's talks with Prime Minister Zhao Ziyang as "frank and sincere" indicated to diplomats that there were differences between the two sides.
Even if temporarily papered over, the differences are substantial.
As one ASEAN diplomat put it to this correspondent, "China wants to humble Vietnam and put a pro-China leadership in power there. We are only against Vietnam's invasion of Cambodia. We want an equilibrium in the area."
The emerging ASEAN consensus seems to be that both China and the Soviet Union should be kept out of southeast Asia as much as possible.
Ideally some sort of political solution through an international conference is needed in Cambodia to keep it from becoming a battleground between a China-backed Khmer Rouge and a Soviet-backed Vietnam.
Thus while in China Prime Minister Prem called for a settlement taking into consideration the interests of all concerned parties. The tone of his comments contrasted sharply with the single-minded repetition by Chinese leaders of their country's demand that Vietnam simply get out of Cambodia.
Another sign of the new ASEAN shift was Prime Minister Prem's announcement that a high-ranking Thai delegation would go to Moscow shortly after his return from China.
There are reports that Malaysian Foreign Minister Tengku Ahmad Rithauddeen plans a trip to Vietnam, probably in early November.
But there are also many Thais who wonder if China can or would fully protect them from Vietnam. For them a settlement that improves relations with Vietnam is attractive.