DURING THE coldest days of the Cold War, an announcement proclaiming a "great reconciliation" between the Soviet Union and China would have produced justified anxiety in official Washington. Today, it can afford to be more detached, and relaxed.
Soviet President Mikhail S. Gorbachev and Chinese leaders patched up many -- though not all -- of their differences last week, ending 30 years of hostility with pledges to restore more normal relations.
The world's two largest communist nations agreed to have more contact between their respective Communist parties, to reduce their military forces along their borders and not to seek "hegemony in any form in Asia."
They continued to disagree on what to do about Cambodia, where they back rival groups. But the tone of their joint communique was conciliatory. And Soviet-backed Vietnamese troops are, after all, withdrawing from Cambodia, an exodus expected to be completed in September.
"A long period of mutual alienation is now behind us," Gorbachev said.
It is a trend that, 30 years after the Sino-Soviet split, Washington need not fear.
U.S. relations with China's present leaders are positive, and the Soviet Union under Gorbachev has been sounding the theme of detente, not adventurism. Equally important, internal dynamics are forcing both Moscow and Beijing to concentrate more on accommodating events within their own borders.
At the moment, these dynamics are pushing both nations, within limits, in directions favorable to the United States. Both seek friendlier relations with Washington. Both want expanded contacts, commercial and otherwise, with America.
And China's leaders, evidently determined not to slip back into any relationship with the Soviet Union that reduces them to a subservient position, continue to insist that normal ties with Moscow do not mean bad relations with other nations, particularly the United States.
The intent of China's leadership to insist on equality in its relationships with the Soviets is something Washington should foster and accommodate.
Nor could anything be clearer -- during a week when massive demonstrations by Chinese protesters for greater freedom disrupted schedules in the Gorbachev visit -- that China today, like Russia, wrestles with great social dissatisfaction and yearnings for more liberal economic and political systems.
To date, China has moved faster than the Soviets in introducing free-market devices in the economy; the Soviets have moved more rapidly in introducing mild democratic reforms in their political system.
But these healthy trends toward freer markets and greater democracy, while extremely modest by American standards, still find their strongest roots in the West and particularly in the United States.
That, too, cannot displease Washington. Whether or not the Cold War is completely over, a deep thaw has plainly set in.