Thailand unlikely to have seen its last coup. Coups seen as fast track for officers to top of military hierarchy

In a break with post-coup tradition, the Thai government has arrested about 30 men following the attempted takeover of Sept. 9. They include a former prime minister, Gen. Kriangsak Chomanand; a former armed forces supreme commander, Gen. Serm na Nakhon; and a number of labor leaders.

The large number of arrests appears to indicate the government's embarrassment over publicity in the wake of the coup attempt. But many observers, both Thai and foreign, feel that the government's investigation into the affair has so far unearthed only part of the story behind the attempt. And though the last uprising failed ignominiously, there is no sign that military coups are a thing of the past. Last week's events once again underlined the political power and influence of Thailand's military.

The government investigation has so far failed to uncover any sign of what one experienced coup organizer, Col. Prachak Sawangchit, calls the ``invisible man'' -- a senior officer who theoretically was involved in planning the coup attempt and could have provided -- but didn't -- the firepower to ensure the attempt's success.

``Kriangsak, Serm, and the others were professional soldiers,'' said Colonel Prachak, an associate of Col. Manoon Roopkachorn, who is said to have planned the latest coup attempt.

``And they were professional coup leaders. So why only 22 tanks and 500 men? Impossible. There must have been some very big VIP behind the scenes,'' Prachak added.

Many Thai and foreign observers doubt that the investigation will look too hard for Prachak's invisible man.

``If the investigation pinpointed big military people, the officers concerned might feel themselves pushed into a corner,'' said Supatra Masdit, spokeswoman for the Democratic Party, which is part of the coalition government of Prime Minister Prem Tinsulanonda (a former general). This could result in another attempted overthrow. But, Ms. Supatra continued, senior officers are careful to cover their tracks when planning a coup. ``They usually make sure that only their aides make contact with coup organiz ers.''

Prachak, who was dismissed from the Army along with Colonel Manoon after leading an unsuccessful coup attempt in April 1981, says that Manoon had discussed a coup with him five months ago.

``Manoon believed the country needed major surgery immediately,'' said Prachak. Prachak says he agreed with Manoon's main grievance -- the weakness and indecision of the prime minister. ``Every day that Prem is our prime minister the country is weaker,'' Prachak said.

But he felt a coup would be impracticable: The former officers involved in the 1981 coup attempt -- the so-called ``young turks'' -- did not control enough men.

Prachak says that Manoon was pinning his hopes on the outcome of the annual military promotions -- long a catalyst for coups in Thailand. ``Manoon said that if some senior officers are unsuccessful in the reshuffle, they should support [a coup],'' he explained.

This year's reshuffle brought to unexpected primacy Gen. Chaovalit Yongchaiyuth, largely at the expense of long-time rival, Gen. Pichit Kullavanich. General Chaovalit, a close adviser of Prime Minister Prem's, was promoted one rank and made Army chief of staff-designate. His position becomes operative Oct. 1. General Pichit, who is closer to Supreme Commander Arthit Kamlang-ek than to the Prem, was kept in his current position as commander of the important first military region.

Colonel Manoon and his brother, Wing Comdr. Manat, are both still at large. Manoon was flown to Singapore in a military plane when the coup attempt collapsed. This was described at the time as part of a deal between government and plotters to avoid further loss of life. Manat is said to be hiding out near the Thai-Burmese border.

The arrest of the alleged coup leaders suggests that the government is deeply embarrassed by the adverse publicity generated by the attempt. Much of this stemmed from the fact that two Western newsmen -- Neil Davies and Bill Latch, both of NBC -- were among the five people killed. The publicity has been kept alive by allegations from other journalists present that rebel troops continued to fire on them as they removed Davies's body. If convicted, the plotters could face the death penalty or life impriso nment, although it is thought that many military men would be loath to see heavy sentences imposed on people like Kriangsak and Serm, their former commanders or patrons.

Until now, leading a coup attempt had the potential of proffering big rewards, since such an attempt was often a sign of power struggles within the military hierarchy. The only recent exception was a coup attempt in 1977, when a senior military officer -- the alleged leader of the uprising -- was executed. But otherwise, failed coup leaders generally have been given little more than a slap on the wrist. The young turks who joined Prachak and Manoon in the 1981 attempted coup, for example, were until rec ently still hoping to return to active duty.

Last week's attempt pinpointed once again the vulnerability of such nonmilitary institutions as the Parliament. Civilian politicians and the Cabinet had to wait on the sidelines for the military to restore order. Then, once the coup attempt was crushed, the prime minister moved quickly to forestall any discussion of the attempt in Parliament, apparently fearing that it would heighten, rathen than diminish, political tension.

The armed forces have dominated politics since a constitutional monarchy was established in 1932 -- and continue to do so now. Since 1932 military prime ministers have held office for about 42 years, civilians for only 11. The Army remains suspicious of what it perceives as the selfishness and disorderliness of civilian politicians. And coups remain a fast track to the top: The prime minister, the current supreme commander, and the rest of the military hierarchy have all been involved in coups or attempted coups during their careers.

Soon after last week's uprising was crushed, a military aide to one of the generals supposedly involved in suppressing it said he did not want to rule out a ``coup option'' in the future. And Colonel Prachak, asked whether he expected to see coups in the future answered without hesitation: ``Sure. One hundred percent.''