Bangkok — Both the Vietnamese and their Southeast Asian adversaries are describing the current fighting along the Thai-Kampuchean border in the same terms -- as a turning point in the struggle for control of Kampuchea (Cambodia). Both parties are convinced that the turn of events will ultimately favor themselves.
In the last few months the Vietnamese have destroyed nearly all of the border camps run by the tripartite Coalition Government of Democratic Kampuchea (CGDK) -- an uneasy alliance of Pol Pot's communist Khmer Rouge and two noncommunist factions, headed by Prince Norodom Sihanouk and former Prime Minister Son Sann. The Vietnamese hope to destroy the coalition militarily and to break the will of its foreign backers -- the Association of Southeast Asian Nations (ASEAN), China, and the United States.
But the ASEAN position has hardened during the present fighting. ASEAN diplomats say that recent setbacks will force the coalition to change its tactics from static warfare to mobile guerrilla operations deep inside Kampuchea.
In the past, ASEAN preferred not to discuss military aid openly. But last week it called publicly for military support for the guerrillas, and it will almost certainly increase its pressure on the US to start aiding the guerrillas militarily.
Hanoi's most spectacular military victory -- the capture late last week of the major Khmer Rouge base complex of Phnom Malai -- was done with surprising ease. Vietnamese sources say the capture of Phnom Malai was the end of a phase of the offensive, not of the offensive itself. Hanoi will probably keep a sizable military presence along the border in an effort to deny the CGDK its old bases. But the Vietnamese will also turn their attention to guerrilla bases in the interior of Kampuchea.
One area they will probably concentrate on is a series of Khmer Rouge strongholds in the coastal province of Koh Kong. Phnom Malai was the closest the Khmer Rouge had to a civilian capital. But the military headquarters seems to be in Koh Kong. Pol Pot, who is still the overall military and political commander of the Khmer Rouge, is thought to spend much time in this area. The Vietnamese will probably also try to break up guerrilla concentrations around Tonle Sap, the lake in the middle of Kampuchea.
The present Vietnamese offensive, the most violent since the overthrow of Pol Pot in 1979, seems to mark a new, aggressive approach to the Kampuchean guerrillas.
Until this year, the Vietnamese leadership seemed to favor combining diplomacy and carefully modulated military offensives in their search for a solution.
This year, however, the leadership seems to have decided to go all out for a military solution. If they do not succeed in destroying the coalition this year, sources close to Hanoi suggest, next year's dry season will probaly see more tough fighting.
ASEAN, however, is trying to look on the bright side.
``The Vietnamese have done us a favor by destroying the border camps,'' a diplomat from a hard-line ASEAN country said yesterday. ``All along we've been telling the coalition to fight guerrilla tactics. Now they've finally realized their mistake.''
ASEAN seems to want a complete rethink of coalition tactics. The main points apparently include:
Completely separating coalition guerrillas and civilian refugees. The present fighting has displaced nearly all the Khmers living in CGDK bases along the border. Some 240,000 are now living in temporary camps administered by the United Nations Border Relief Operation.
Setting up small, secret logistics bases -- bridgeheads for the delivery of military supplies -- in place of the big CGDK border camps. ``No more black-market and rest-and-recreation areas,'' an ASEAN diplomat said yesterday, referring to the old camps. ``The new ones have to be purely military.''
Having small-unit guerrilla operations move deep inside Kampuchea.
ASEAN sources claim that the new approach is already being put into action. Although the Chinese have not yet struck hard at Vietnam's northern border, ASEAN sources say that Peking has provided a substantial amount of new supplies to the coalition. One informed source said yesterday that in the last six weeks the Chinese had flown in a ``huge amount of weaponry'' for the noncommunist guerrillas. This included antitank weapons, mortars, machine guns, and ammunition.
ASEAN also may be preparing to press the Reagan administration to arm the coalition.
At the moment, one ASEAN source said, the US is almost the biggest financial backer of the noncommunist CGDK factions. But, he continued, ``We would like to see the US become the major military supplier of the CGDK noncommunists. We're only asking for military aid, not ground involvement. And it would be much cheaper than Afghanistan.''
The only border camp to remain unscathed so far is Tatum, the headquarters of Prince Sihanouk's small military force. This is probably because Hanoi is still trying to entice Prince Sihanouk -- who is not fond of Son Sann and hates Pol Pot -- out of the coalition.