Both sides in Kampuchea conflict arm for next offensive

Thailand says the Vietnamese dry season offensive has started. Vietnam says there isn't going to be an offensive.

Whichever claim is right, there are a lot of weapons heading for both sides in the Kampuchean (Cambodian) crisis.

Singapore, one of the more enthusiastic backers of the anti-Vietnamese coalition government of Democratic Kampuchea within the Association of Southeast Asian Nations (ASEAN), regularly refuses to comment on reports that it has provided weapons to coalition members. But reliable reports say Singapore recently sent two shipments of arms to Son Sann's Khmer People's National Liberation Front (KPNLF).

(Ending a two-day visit to Thailand recently, Malaysia's Prime Minister Datuk Seri Mahathir affirmed that his government would provide moral and political support to Son Sann's anti-Vietnamese coalition, but not military aid.)

The first batch of military hardware from Singapore, about 2,700 rifles, ammunition, detonator caps, and other items, was reportedly sent late last August. A second batch with some 1,600 guns was sent in October. This may well be the third shipment of weapons Singapore has sent to the KPNLF, as it was reported to have sent aid to Son Sann late last year.

Last year's shipment was reported to consist of M-16 rifles, which the Singapore government's own chartered industries made under license until December 1979. This time, intriguingly enough, the guns are said to have been Czech-made AK-47s, the standard assault rifle of the Eastern bloc. Most accounts imply that Singapore bought the weapons on the international market, probably from a third-world country.

The shipments are undoubtedly welcomed by the KPNLF, which is said to number between 9,000 and 12,000 men. The arms, however, increase the pressure on its military commanders to engage the Vietnamese and Heng Samrin forces this dry season, and Singapore would probably think twice about sending any more weaponry if the KPNLF is not seen to be making active use of its present aid.

Singapore's aid may also increase Vietnamese interest in the KPNLF. Vietnamese officials have hinted that if there is any dry season activity this year by their troops, it would be in response to the other side's ''provocation.''

Singapore is the only ASEAN member known to have given the coalition arms, and most if not all its assistance has gone to Son Sann. The Khmer Rouge do not qualify for assistance because of their murderous past - ASEAN is happy to leave supplying them to China - while Prince Sihanouk is considered by many Singaporean officials to be ''too much of a clown,'' as one official put it, with not enough organization to merit support.

The Chinese think more of the prince, but they do not give him many supplies either. Sources close to Peking acknowledge the prince's important political role inside Kampuchea, where he still has a sizable following among the peasantry. ''If there were free elections in Cambodia today, Sihanouk would undoubtedly win,'' one of these sources remarked. But they add, sadly, that the prince's lack of a political and military structure precludes their offering military aid.

Chinese support for the Khmer Rouge, on the other hand, seems undiminished. Khmer Rouge troops this year are ''better prepared with weapons, ammunition, and food (from China) than for many years,'' an informed source said. The source added that the Khmer Rouge had made some recruits this year, a claim advanced by Bangkok-based military analysts both sympathetic and hostile to the coalition.

If correct, this would probably testify to the usefulness of Prince Sihanouk. As the Vietnamese themselves sometimes complain, the Khmer Rouge use of the prince's name has given them a degree of access to Khmer villagers that they would otherwise not have been able to attain.

One other key actor in the Kampuchean drama has faded out of the limelight but still seems to be very active behind the scenes - Pol Pot. Sources close to Peking make it clear that while Khieu Samphan is the figurehead Khmer Rouge leader, Pol Pot is still the ''key cadre'' of the movement. Chinese officials are reported to meet Pol Pot quite regularly on their visits to Khmer Rouge camps near the Thai border.

It is much harder to obtain a picture of military aid going to Vietnam. Noncommunist shipping sources say that the ships in Ho Chi Minh harbor last month were abruptly ordered to leave port while two large Soviet freighters, capable of carrying some 20,000 to 30,000 tons of cargo, unloaded. The sources say the goods unloaded were armaments.

Other more official Western sources claim that about 10 ships a month have been calling on Vietnamese, or occasionally Kampuchean, ports. Each carries about 10,000 tons of cargo. An ''educated guess'' tells these sources that the cargo is arms. This has been going on for the last four to five months, the sources add.