As the new Sino-Soviet "political contacts" resume in Peking, diplomats here are in general agreement that the talks could last months or years and possibly exacerbate, rather than resolve the feud between the two Communist powers.

According to these diplomats, who include both Soviet and Chinese sources, no quick or major changes can be expected in a relationship NEWS ANALYSIS burdened by hostilities and acrimony ever since Mao Tse-tung and Nikita Khrushchev fell out in the early 1960s.

Yet the resumption of the talks yesterday is a sign -- admittedly faint -- of less strained relations between the once grimly contentious Communist giants.

The tantalizing question is whether this represents a potential turning point in their relations or is merely a tactical ploy both are using to influence their relations with the United States.

Most diplomats believe the latter. President Reagan's Taiwan policy is said to have motivated China to send a warning to Washington that the Sino-Soviet feud may not be a permanent feature of international life and that Peking is now prepared to play its "Russian card" to back up its stand on Taiwan.

That both nations want broader political dicussion now is, nevertheless, a major diplomatic breakthrough. For Moscow, which has been wooing the Chinese and urging them to normalize relations, the talks hold out the prospect of a lessening of tensions on the eastern front. The Russians apparently believe that even the possibility of their rapprochement with China would put the United States off guard.

By establishing these "political contacts" with Moscow, the Chinese appear to be asserting their role as a world power. While not yet a superpower, China, by virtue of its size and its increasing emergence on the world scene, holds a special position between the two superpowers.

The Sino-Soviet dispute has been one of the key factors in international politics for more than a decade. It has preoccupied the two Communist countries with each other, giving the United States additional leverage against both, while at the same time symbolizing the collapse of a united worldwide Communist movement.

The resumption of Sino-Soviet political dialogue, even if it is grounded in tactical objectives by the two sides, appears to signal the possibility of change in the triangular relationship. Both China and the Soviet Union seem to be calculating that their relations with Washington could be influenced by the degree to which they can change their bilateral relations.

Some analysts here argue that, depite tactical considerations, both sides have genuine and substantive interests in easing tensions, particularly along their border.

After drifting apart over ideology, territory and other issues, the two countries reached a low point in their relations when they fought a small border war in 1969. Low-level border talks were opened that year and continued intermittently until 1979.

But the border talks, as well as the first political negotiations in the fall of 1979, were interrupted by the Soviet invasion of Afghanistan. During the last year of the Carter administration, China's propaganda war against Moscow was escalated with Peking calling for the establishment of a "united front" against the Soviet Union.

With President Reagan in the White House, and the downturn in Sino-U.S. relations, the Russians have moved decisively to take advantage of Peking's unhappiness over Reagan's proposed sales of U.S. jet fighters to Taiwan.

President Leonid Brezhnev has declared publicly that China is a socialist country after all. An authoritative article in Pravda last July argued that the Sino-Soviet feud was being promoted by the West to "bleed white" both China and the Soviet Union.

Pravda suggested that both sides, and particularly the Chinese, would benefit from an easing of border tensions. China's modernization program needed a thaw in Sino-Soviet relations, and the Chinese are maintaining troops not only along their border with the Soviet Union but also along the Vietnamese frontier.

Brezhnev again underscored Moscow's desire for improved relations in a dinner speech tonight for visiting Vietnamese President Truong Chinh.

The Vietnamese, whose relations with China have been tense since the 1979 Sino-Vietnamese border war, have sent a high-level delegation here presumably to express concern about Moscow's attempts at rapprochement with Peking. But an official communique said Brezhnev and Truong both expressed the hope for more normal relations with China.

Western diplomats here expect the Chinese to be extremely cautious at the preliminary political negotiations. Apart from disagreements over Afghanistan and Southeast Asia, there are Chinese grievances at what they see as Russian exploitation over the past 150 years. There is also the question of Mongolia, which Peking believes should fall in China's sphere of influence as it did before 1911.

Moreover, there are residual Chinese territorial claims to large expanses of land taken by the tsars under what Peking calls the "unequal treaties" imposed on weak Chinese emperors. To top it all, there are specific territorial claims.

The Chinese have made it clear that they do not hope to reincorporate all these areas, now populated by Soviet citizens. But they have sought "reasonable" adjustments.

According to qualified Chinese sources here, Peking wants to improve its ties with Moscow without going back to the relationship that existed in the 1950s. China, one source said, "will never again be a member of the Soviet Bloc." The Chinese make it clear that they want to expand economic and other links with Moscow.

The same sources said Peking also wants to maintain its relations with Washington despite the Taiwan issue. They described as "not acceptable" to China what they said was Washington's compromise formula under which the United States would supply Taiwan with new weapons only if China were to acquire more modern arms.

As one Asian diplomat put it, the latest developement in Sino-Soviet relations places Washington in a delicate situation. The Reagan administration, he said, obviously cannot cave in to Chinese pressure. Yet the United States must be careful in its dealings with the Chinese so as not to push them into turning what is for the moment a tactical ploy into something more substantial.