If the infectious disease SARS breaks out around the globe, it most likely will come from the People’s Republic of China, the world’s most populous state with a primitive health-care system and vast rural population. If SARS spreads from China, the cause will be the Chinese government’s long refusal to deal honestly with a serious problem that swiftly turned into a deadly crisis.

After unconscionable delay, Beijing has acknowledged the severity of the epidemic and dismissed a number of officials for mishandling the issue. Prime Minister Wen Jiabao stated at the recent Association of Southeast Asian Nations meeting in Bangkok: “The Chinese government is here in a spirit of candor, responsibility, trust and cooperation.”

Fine words, but China continues to oppose an important step that would help combat SARS and other threats to human health — allowing Taiwan observer status at the World Health Organization. The United Nations may be generally ineffective, but if there is an obvious place for international cooperation, it is combating transnational medical epidemics. And the WHO has been most everywhere during the current crisis. Except to Taiwan. Only in May did the organization send two experts to Taipei. The problem is politics. The People’s Republic of China claims sovereignty over the island of Taiwan, separated from China throughout the 20th century — first occupied by Japan and then the home of the nationalist government ousted by the communist revolution.

When the United States warmed relations with Taiwan in 1971, Taiwan lost its membership in the U.N. General Assembly and most ancillary international organizations, such as the WHO.

Taiwan’s isolation is senseless. The vast majority of Taiwan’s 23.5 million people want to maintain their island’s independent existence after a century apart from China. Taiwan has a larger population than three-quarters of U.N. members and its people have created a vibrant, capitalist, democratic state — something to which the vast majority of nations can only aspire. Taiwan retains the recognition of a score of mostly small countries and has been allowed to participate in some international forums through various guises, such as a “customs territory” in the World Trade Organization. But Taiwan remains outside the WHO looking in.

Beijing naturally wants to keep Taiwan isolated. A Chinese diplomat told journalist Jonathan Mirsky: WHO observer status “is a Taiwanese trick for getting into international organizations.” For this reason, Beijing even blocked WHO officials from visiting the island after a massive earthquake in 1999.

But observer status confers no international legitimacy. After all, WHO observers include the Palestinian Liberation Organization, Vatican, Red Cross, and Sovereign and Military Order of Malta (The Sovereign and Military Order of Malta!?). Excluding Taiwan is the real political trick. Mainland China’s obstruction wouldn’t matter so much if there were no practical impacts of Taiwan’s exclusion. But that exclusion has contributed to the spread of SARS.

Taiwan is at great risk, given the island’s substantial cultural, familial, and economic ties with China. Yet for a time the WHO didn’t even acknowledge the outbreak of the disease in Taiwan. The Taiwanese government has responded with tough measures and international openness — in stark contrast to Beijing — but Taipei may find it difficult to isolate itself if infections continue to spread across Taiwan. And if Taiwan is at risk, so are other states.

Despite its relatively small size, Taiwan is one of the globe’s most important trading nations, ranking 14th. It also is home to hundreds of thousands of migrant workers from throughout East Asia. By excluding Taiwan, even as an observer, the WHO bars Taiwan from its Global Outbreak Alert and Response Network, which transmits information about medical epidemics and member health activities. This slows information-sharing and impedes the provision of practical assistance, which must be channeled through indirect and informal mechanisms. Taiwan’s isolation also prevents it from contributing to international relief efforts. Indeed, despite the seriousness of the SARS outbreak, the WHO rejected Taiwan’s initial request to cooperate. Yet Taiwanese medical professionals have worked with the WHO as consultants; Taiwanese non-governmental organizations have provided health-care assistance around the world.

Taiwan’s government has contributed more than $120 million to 78 countries for health care since 1995. Taipei has even donated $5.7 million for a SARS project in cooperation with China and Hong Kong. But Taiwan cannot work with the WHO. The World Health Assembly is meeting through May 28 in Geneva, and 21 of Taiwan’s allies are attempting to push its participation as a “health entity” onto the organization’s agenda. But Beijing dismisses such “interference in China’s internal affairs.” The PRC’s claim over Taiwan reflects the worst sort of nationalist passions. But Beijing and other members of the WHO should set aside politics in the face of a life-threatening epidemic. Taiwan belongs in the World Health Organization.