GORBACHEV IN CHINA : Sino-Soviet Thaw Affects Progress on Accord : Summit’s Shadow Falling on Cambodia

At a news conference here recently, Cambodian Premier Hun Sen held up a drawing of a flag that had been hastily scrawled in red, blue and yellow crayon.

It was the new flag of Cambodia, Hun Sen said, and its design had been agreed to in talks between his government and Prince Norodom Sihanouk, the former Cambodian head of state who now leads a three-party coalition in opposition to the government in Phnom Penh.

Despite the theatrical overtones, the talks were not about color schemes but evidence of a remarkable transformation in the political climate in Indochina. After a decade of hostility, two enemies were negotiating to end one of the region’s most intractable conflicts.

It was no coincidence that Hun Sen’s talks with Sihanouk took place just two weeks before the start of this week’s Sino-Soviet summit. Indeed, according to Western and Asian diplomats in the region, it was largely the events leading up to the summit that helped set the stage for progress toward a Cambodian accord.

China for years had listed three issues standing in the way of improved relations with Moscow: Sino-Soviet border tensions and the issues of Afghanistan and Cambodia. Some diplomats said that after the Soviet Union withdrew its troops from Afghanistan, Cambodia acquired greater importance than even the border problem.

Since December, 1978, when Vietnamese troops invaded Cambodia and deposed the Khmer Rouge government, the Cambodian conflict had many elements of a proxy war between the Soviet Union and China.

Massive Assistance

Moscow supported Vietnam with military and economic assistance that made its continued occupation of Cambodia possible. China gave massive assistance to the Khmer Rouge in exile in Thailand, then helped forge the resistance coalition led by Sihanouk when it became clear that the Khmer Rouge, blamed for 1 million deaths during its 3 1/2-year rule in Cambodia, was unpalatable to much of the world community.

The Khmer Rouge kept the Vietnamese army occupied for a decade and cost Vietnam at least 55,000 soldiers, according to statements from Hanoi. Meanwhile, the regime in Phnom Penh, supported by Vietnamese troops, has been shunned by most of the world community except the East Bloc.

All of that started to change after Mikhail S. Gorbachev came to power, calling for an end to regional conflicts and undertaking a program of perestroika --restructuring the Soviet economic and political system. This had implications for Soviet allies such as Vietnam.

In March, 1987, after Soviet Foreign Minister Eduard A. Shevardnadze toured Southeast Asia--his stops included Cambodia and Vietnam--the governments in Phnom Penh and Hanoi announced their willingness to seek a political settlement in Cambodia.

When it became clear that the timetable for Vietnamese withdrawal from Cambodia was a stumbling block in the negotiations and thus a possible point of friction at the Sino-Soviet summit, Vietnam announced in April that it was moving up the withdrawal date of its troops to Sept. 30, 1989. In a further shift of position, it said the withdrawal would take place regardless of whether there was a political settlement in Cambodia.

Moscow’s interest in solving the Cambodia dilemma was clear: Its allies in Hanoi remained internationally isolated, and the conflict was costing Vietnam an estimated $3 million a day, an economic drain that neither country could afford.

Soviet pressure on Hanoi was evident in Moscow’s insistence that the negotiations include all four parties to the conflict, including the Khmer Rouge, while the Vietnamese wanted the Khmer Rouge to have only a minimal role in a settlement, if any.

China, for its part, began to speak of limiting the Khmer Rouge role in any settlement, even though Beijing had been the Khmer Rouge’s patron for more than a decade.

China and Vietnam have had centuries of unfriendly relations as Beijing sought to limit Hanoi’s power and influence in the region. These hard feelings were submerged during the Vietnam War, when China helped Vietnam, but they resurfaced after Hanoi’s victory in 1975.

Sino-Vietnamese tensions rose when Hanoi began curbing ethnic Chinese businessmen in southern Vietnam, prompting an exodus of Vietnamese Chinese.

China canceled its economic aid to Vietnam, leaving Hanoi increasingly dependent on Moscow, and this led to Vietnam’s joining Comecon, the East Bloc economic group. In 1978, Vietnam signed a treaty of friendship and cooperation with the Soviet Union, which provided the Soviets with facilities at the Cam Ranh Bay naval base.

Relations steadily deteriorated, culminating in the February, 1979, Chinese invasion of Vietnam.

The short border war with China was one more heavy burden on Vietnam, which had realized few benefits from the period of peace since the end of the long Indochina conflict in 1975.

In June, Vietnam revised its constitution to delete references to China’s “hegemonists”--those who seek dominance over other countries--and sent a deputy foreign minister to Beijing in the first such visit in eight years.