In his rush to achieve glory at home and respectability abroad, China's Jiang Zemin keeps slipping on the banana peels of totalitarian rule.

The Chinese president had set his sights high in this final year of the millennium, which also marks his Communist Party's 50th year in power. But a series of mishaps, miscalculations and missteps has undermined Jiang's hopes for a glittering and personally triumphant celebration in a month's time on the anniversary of Mao Zedong's revolutionary victory in Beijing.

China's once-strong economy is stumbling. Jiang's ambition for clear progress this year on reuniting Taiwan with the mainland has been openly challenged by the island's leaders. Beijing's promises not to interfere in Hong Kong's affairs are being abandoned. Heavy repression of the peaceful Falun Gong religious movement and of political dissidents also taints the atmosphere.

Most dramatic, Jiang's plan to showcase a strategic partnership with President Clinton lies buried in the debris of the Chinese Embassy in Belgrade and the last-minute failure of Washington and Beijing to agree on new global trading rules. In each case, the angry reaction of Beijing's hard-liners has done more damage to diplomatic ties than the event itself.

Now -- just as Jiang has a chance to smooth over U.S.-Sino tensions in a September meeting with Clinton and restore luster to his leadership halo -- heavy-handed police tactics used on an American citizen are reviving pressures on Washington to keep its distance.

Jiang clearly would have had nothing to do with the arrest and brutal interrogation of Daja Meston, a Tibetan linguist from Newton, Mass., on Aug. 15 in the remote northwestern province of Qinghai. This is probably the last thing Jiang would have wanted to happen just now.

But these unforeseen or unplanned incidents all reveal the true nature of the system that Jiang dominates but does not control. A half-century of isolation under a Communist dictatorship -- that is what the October anniversary represents -- leaves its marks and its methods deeply entrenched.

That half-century has instilled paranoia and a demand for total control in the police, military, censors, Communist Party cadre and other parts of the repressive state apparatus. The totalitarian reflex can surface at any time, against anyone.

It came into play forcefully when Meston, 29, an Australian colleague and their Tibetan interpreter began asking questions this month in Qinghai about a plan to resettle ethnic Chinese farmers onto nearby traditional Tibetan lands. The three men were taken into custody, charged with "illegal investigating" and questioned so aggressively that Meston apparently jumped from a third-story window to escape his interrogators.

He is now in a Chinese hospital with a broken back. The Australian has been expelled. Ominously, the fates of the interpreter, Tsering Dorje, and of a dozen local residents who talked to the trio and were rounded up, are unknown.

Just another day in a police state. But this tragic incident should have wider repercussions. It should doom whatever chance China had of receiving the $40 million World Bank loan Beijing had requested to finance the resettlement scheme. It should cause the bank and other international lending institutions to reexamine their overly cozy relations with Beijing.

The bank's stamp of approval on the colonization project was far more important to Beijing than the $40 million, which the regime can easily replace from its own coffers. The scheme was under attack from activists concerned about Tibetan culture and from environmentalists.

To secure World Bank participation, the Chinese government promised open access to the area and has arranged tours for journalists. But when Meston arranged his own tour, that part of the system not devoted to public relations struck back.

The World Bank is required by its own rules to make sure that local residents are meaningfully consulted on the projects it finances. How such consultations can be carried out in a political system that routinely represses and punishes free speech seems to be a question the bank's staff has not thought through.

The Clinton administration wisely opposed the World Bank loan and succeeded in getting it put on hold in June. When the two meet next month for informal talks at the annual Pacific Rim trade summit in New Zealand, Clinton should forcefully raise the Meston case with Jiang. The American president is under no obligation to help Jiang put a series of embarrassments behind him in time for the Communists' October birthday party in Beijing.