Despite US airlift of arms, Thailand still frets over more powerful Viets

The much-publicized US military airlift to Thailand two weeks ago has done little, if anything, to redress the country's military balance toward the Vietnamese.

And Vietnam's incursion across the Thai-Cambodian border last month has prompted a sober reassessment of Thailand's security by leaders in Bangkok.

The officials are taking stock of the less-than-rosy security situation along its borders with Cambodia (Kampuchea) and Laos, both of which are dominated by Hanoi.Although most analysts, including some Thais, agree that a concerted Vietnamese drive into Thailand is unlikely, the political and military options available to Bangkok in the case of such a move are very limited.

Militarily, the entire Thai Army of 145,000 is outnamed by the 160,000 Vietnamese forces stationed in Cambodia and Laos. Hanoi's battle-hardened standing army totals 1 million men. Nor can the Thais, with their one cavalry division and four tank battalions, match Vietnam's 1,500 tanks in hardware.

All that the touted US airlift brought in was 18 howitzers (105 mm), 38 recoiless rifles (106 mm), 1,000 assault rifles (M-16), and ammunition to go with them. The net addition next month will be 35 tanks (M-48) and some more artillery and ammunition. All this is being supplied under the $40 million military aid package agreed to by the United States.

Although China has unequivocally supported Thailand against Vietnam, Peking's military supplies -- small arms and mortars -- have gone only to the Pol Pot Khmer Rouge guerrillas. China is unlikely to give any sizable military hardware to the Thais. Its capacity for such aid is limited. A Chinese entry into Thailand would strengthen the Vietnamese resolve and give further opportunity to Moscow to intensify its hold over Indo-China, a prospect unwelcome to Peking.

A military tie-up with China could prove a mixed blessing for the Thais and their friends in the Association of Southeast Asian Nations (ASEAN). Most ASEAN diplomats privately concede that although Vietnam is an immediate threat to the stability of the region, China poses a long-term element of uncertainty.

Of late, Singapore Prime Minister Lee Kuan Yew has been talking of the possibility of ASEAN military cooperation if Thailand's security is threatened. But analysts treat it as more rhetoric than substance.

So the Thais' only realistic military recourse is to the US. The Carter administration last year repeated the US commitment to Thailand under the 1954 Manial pact, which requires the US to come to the Thais' aid if they are threatened by communist aggression.

In the event of a Vietnamese attack, immediate US assistance could come in the form of air strikes from US bases in Okinawa and the Philippines. The only US ground troops in the region are in South Korea and Japan, but their numbers could prove ineffective, if Hanoi is bent on a large-scale offensive. All this assumes, however, that a US president has overcome the domestic political hurdles of waging another war on the Asian mainland.

With such a grim military picture, Thai and other ASEAN leaders are groping for a political solution for Cambodia. China wants to reverse the existing situation there, while Hanoi has resolved that it is irreversible. ASEAN wants to see a neutral regime.

Amid such irreconcilable goals, Thailand will have to keep looking the other way while Chinese arms continue to flow to Pol Pot guerrillas and while the Hanoi-backed Heng Samrin regime tries to bring order to Cambodia. Thai generals , meanwhile, are hoping that Hanoi and Moscow will not escalate the conflict further.

For all the sobriety over the country's military posture, the mood in Thailand the past couple of weeks has been upbeat.