Not long after the World Health Organisation issued a global health alert for a new, deadly form of pneumonia that it dubbed Sars, governments around the region started to take action to protect their people, largely by keeping out travellers from other countries believed to be potential sources of infection or by imposing tight restrictions on their activities. Not surprisingly, those targeted frequently adopted retaliatory action, so that a series of tit-for-tat measures ensued. Thailand was one of the first to act, deciding on April 2 that visitors from certain countries and regions - including Hong Kong, the mainland, Vietnam, Taiwan and Singapore - should undergo physical checkups upon arrival and wear surgical masks throughout their stay. Taiwan, one of those targeted, was particularly enraged by the measures, especially since it was not covered by the WHO's travel advisory, which included only Hong Kong and Guangdong province. Subsequently, the Taiwan government weighed retaliatory action. Chen Chu, head of the ministerial-level Council of Labour Affairs, said it would consider either cutting the number of Thai workers or halting the import of any new ones. With more than 100,000 Thais employed in Taiwan, such a move would have a significant economic impact. Thailand was perhaps most sensitive to the potential ravages of Sars because one of the first victims was Carlo Urbani, the WHO doctor in Vietnam who first identified the virus. He had contracted the disease and died in Bangkok only four days earlier. Malaysia, too, was extremely apprehensive about the disease spreading within its population. It announced the suspension of visa-free entry for Hong Kong residents and made clear that those who applied for visas would not be considered unless they possessed a doctor's certificate saying they have not been infected. Hong Kong protested vociferously and Malaysia wavered, deciding first against applying the ban, only to institute it. The Philippines, too, announced it would ban travel to Hong Kong, but relented and said it would only 'discourage all unnecessary travel' to the city. This hesitation on the part of Malaysia and the Philippines reflected the fact that those countries would pay an economic price for any ban. Southeast Asia is a favourite destination for Hong Kong tourists. China also retaliated against countries that restricted visitors from the mainland. It ordered its travel agents to stop all organised tours to Malaysia, Thailand and Singapore after those countries imposed restrictions. As Thai Prime Minister Thaksin Shinawatra said, Sars had created an atmosphere of mistrust among countries in the region, with each trying to erect barriers. And so it was a good thing that the Association of Southeast Asian Nations, together with China, Japan and South Korea, held a health ministers' meeting in Kuala Lumpur last Saturday, during which participants agreed that a comprehensive approach was required to contain and prevent the spread of the disease. All participating governments agreed to follow WHO measures for travellers from Sars-affected areas and called for the setting up of stringent pre-departure screening of passengers for international travel. The adoption of uniform standards should bring an end to individual countries' measures and counter-measures. Premier Wen Jiabao, who took part in a summit meeting with Asean leaders in Bangkok on Tuesday, has agreed to lift a ban on travel to Thailand by Chinese tour groups, while pledging to screen all passengers prior to departure. As Chinese tour groups normally also travel to Singapore and Malaysia on package tours, the ban on travel to those countries is likely to be lifted too. However, although most countries in the region may, in future, operate under uniform rules for the screening of travellers, such rules may not apply to Taiwan, which was not invited to any of the Asean meetings on Sars. Taiwan has instituted draconian measures against travellers from what it considers to be Sars-infected areas, including Hong Kong. On Monday, it decided to suspend issuing visas to people from the mainland, Hong Kong, Canada, Singapore and Vietnam. Those permitted to enter Taiwan will be placed in quarantine for 10 days. It would be in the interests of all concerned - Asean, China, Japan, South Korea and other countries - to find some way of ensuring that Taiwan is part of any international agreement on travel. Sars is likely to be around for some time and the virus does not respect international borders or political disputes. Frank Ching is a Hong Kong-based journalist and commentator frankching1@aol.com