Over the years, China and Britain have created a capitalist success story in Hong Kong almost without thinking about it.
Now that Peking and London are talking about Hong Kong's future, there is a possibility that they could puncture that success.
As a result of British Prime Minister Margaret Thatcher's recent visit to China, the two nations have agreed to quickly resolve Hong Kong's status well before a 99-year treaty ends in 1997. Their common aim, all agreed, is to sustain the ''stability and prosperity'' of the tiny territory.
But that's where the common aim may stop. Mrs. Thatcher stressed the validity of the treaties that support British jurisdiction over Hong Kong. And China has repeatedly stressed its intention to regain sovereignty, plus its longtime opposition to ''unequal treaties. The result: Peking and London continue to undermine the fragile business confidence in Hong Kong.
Inside sources indicate that Mrs. Thatcher's talks with Premier Zhao Ziyang and Chairman Deng Xiaoping were devoid of acrimony. The respective positions on Hong Kong were stated for the record, but without any heated argument or attention to detail. Indications are that the negotiations got off to a businesslike start, and there is reason to believe they will continue that way.
But British and Chinese domestic politics inevitably brought differences out into the open. In trying to reassure Hong Kong, Mrs. Thatcher chose the option least likely to offend Chinese sensitivities. She did not insist on Hong Kong being British, as she had with the Falkland Islands. Neither did she insist on directly asserting de facto British sovereignty over Hong Kong.
Instead, at press conferences in Peking and Hong Kong, the British prime minister stressed the continuing validity of the treaties under which Hong Kong Island and parts of the city of Kowloon were ceded to Britain. But these areas are dependent on the New Territories, which were only leased by treaty for 99 years. (Together they make up modern-day Hong Kong.)
Since they came to power in 1949, the Chinese Communists have abided by these treaties in practice, while vehemently opposing them in principle. By also stressing that the treaties could be changed by agreement, Mrs. Thatcher left open the possibility that the Chinese position could be accommodated, provided that Hong Kong prosperity were served by that accommodation.
True to their negotiating style, the Chinese have lost no time in replying to Mrs. Thatcher's assertions with restatements of their own principles. First, the Chinese-controlled media reported Hong Kong comments critical of Mrs. Thatcher's stance. Then the Chinese Ministry of Foreign Affairs and the People's Daily weighed in with predictable assertions about the ''unequal treaties.''
On the one hand, many in Hong Kong have naively assumed that Mrs. Thatcher would concede to this Chinese view as an opening gambit. On the other hand, the open disagreement hardly conveyed a reassuring image to the jittery financial markets in the colony.
Both the Hong Kong stock exchange index and the Hong Kong dollar exchange rate have plummeted since the agreement to negotiate the colony's future was announced.
In part, this reflects Hong Kong's excessive expectations attached to the Thatcher visit. It also reflects the fact that Mrs. Thatcher did not pay as much attention to reassuring Hong Kong as she might have.
The dramatic declines were also due to bad economic news, as the government halved its estimates for economic growth. Previously the gross domestic product was expected to gain 8 percent in 1982. Now the calculation is 4 percent.
While market analysts expect the downward slide of the stock exchange and the exchange rate will to continue for a while, they hope these will not be prolonged. Nevertheless, the nervousness did indicate the difficulties under which China and Britain will negotiate. The talks are likely to be complex, protracted, and secret. As the international economic recession continues, there will be additional reasons for Hong Kong nervousness.
The negative response of the financial markets was not the sum total of Mrs. Thatcher's impact on Hong Kong. ''I think she will try and do a good job for us, '' said one man in the street, as he reacted to Mrs. Thatcher's slightly Confucian stress on Britain's ''moral duty'' and ''moral responsibility'' to the people of Hong Kong.
Mrs. Thatcher's one major speech here, some said, was a disappointment. It seemed to have been drafted with a British audience in mind, rather than a Hong Kong one.
Similarly, as the Chinese assert their political principles over Hong Kong vis-a-vis Britain - much as they have, over the last two years, been asserting their principles over Taiwan vis-a-vis the United States - it remains doubtful whether China has a full grasp of the delicate Hong Kong situation.
As she launched a Hong Kong-owned ship in Shanghai, Mrs. Thatcher referred to the mutually beneficial triangular relationship between China, Hong Kong, and Britain. These comments were not reported in the press in China. Chinese officials, some say, continue to talk to the foreign press as if abstract principles were their only concern, without any hint of the pragmatism which probably lurks beneath the Chinese negotiating posture.