Vietnam's troop reinforcements in western Cambodia have raised tensions in Southeast Asia and threatened to disrupt the delicate equilibrium in the area. Reports that Vietnam has concentrated up to half of its 200,000 troops stationed in the western part of the country have raised concern that at a minimum a large-scale offensive against the China-backed Khmer Rouge is in the offing.
The maximum concern is that there may be a repetition of the June Vietnamese-led attack into Thailand.
Thai military reports that Soviet MIG-21 fighters have been sent to northwestern Cambodia are said to have raised concern among military observers. They note that Thai air superiority helped beat back the June 23 Vietnamese-led incursion.
The tense border situation has led to both military and political responses. Thailand has stepped up its own border preparedness, going so far as initiating air raid drills for the city of Bangkok.
Meanwhile China is reported to have stepped up small military attacks along the border with Vietnam since the June 23 attack on Thailand.
Vietnam first made these charges, later confirmed by Chinese officials to Thai and other diplomats, according to Allan Dawson of the Bangkok Post.
The Chinese aim is apparently to keep Vietnam off balance and prevent a second attack by warning of the possibility of major Chinese retaliation.
Reports of the continuing Vietnamese buildup caused the US State Department to express concern last week. Said spokesman David Passage: "Our intelligence reports are that there has been a step-up in Vietnamese troop activity. We urge Vietnam to honor its promises and refrain from any attacks on Thai territory."
The growing tension has also produced growing unity among the Association of Southeast Asian Nations (ASEAN), of which Thailand is a member. Even Indonesia, often wary of China and eager to maintain "bridges" with Vietnam, has firmly supported Thailand.
President Suharto announced Indonesia's "fullest support" for Thailand's efforts to defend its territorial integrity. In an Aug. 16 speech, the President (without naming Vietnam) called for withdrawal of all foreign troops from Cambodia.
Even, as the ASEAN members (Thailand, Malaysai, Singapore, the Philippines, and Indonesia) rallied together, the Indochina crisis was contributing to a spurt of diplomatic maneuverings.
Thai Prime Minister Prem Tinsulanonda is scheduled to visit China in October.One goal is be to maintain China's support for Thailand.
Singapore Prime Minister Lee Kuan Yew also was to visit China in early October after a trip to the Soviet Union originally scheduled for later this month.
But last week Moscow abruptly cancelled the prime minister's visit on the grounds that Soviet Prime Minister Alexei Kosygin is ill. Besides this, however , the cancellation until some still unspecified time is thought to reflect Soviet displeasure over Singapore's strong anti-Soviet line on the Russian invasion of Afghanistan and the Vietnamese invasion of Cambodia.
Mr. Lee was expected to bring up these issues in talks with Soviet leaders.
Still, Mr. Lee who is often seen as strongly anti-Vietnamese, had been striking a peacemaking note in the weeks before the Soviet cancellation.
After discussions with President Suharto in Indonesia recently, the prime minister declared: "If we are to have a disengagement or lowering of the temperature of confrontation between Vietnam -- backed by the Soviet Union -- and China, there must be a compromise over Kampuchea [Cambodia] in which neither side is seen to have won.
"Continuation of the Heng Samrin regime will thus be a total loss of face for China, while Pol Pot's return will be the same thing for Vietnam."