(CNN) -- Somewhere in rural Asia, a bar-headed goose tramps through fields and puddles and makes itself comfortable inside the home of the farmer who owns her.Somewhere else, chickens outnumber people, and can be found roaming every corner of the community.Rural Asians are used to this constant contact -- it has been that way for centuries.But it's a coexistence that could threaten the worldwide community.The reason: bird flu, or what scientists are calling H5N1. It has been a smoldering threat this time in Asia for almost three years. Millions of birds have been killed either by the flu or by officials killing off flocks of birds to stop its spread. So far, it is blamed for killing more than 60 people.Worse, infected birds have been found as far away as Turkey, England and possibly Canada.This has started the murmurings of a bird flu pandemic among humans."Pandemics, the bottom line is they happen," said U.S. Health and Human Services Secretary Michael Leavitt. "Ten times in the last 300 years, and three times in the last 100 years, viruses have mounted a massive pandemic assault that have made masses ill and caused millions to die. They happened before, they'll happen again and we need to be prepared."The U.S. is preparing with a proposed $7.1 billion plan to fight the bird flu, with most of the funding aimed at improving vaccine production and stockpiling anti-virals like Tamiflu.President George W. Bush said stopping the disease at its source is an integral part of the plan.But only a small part of the Bush plan's budget -- $251 million -- would go toward surveillance in other countries, what many experts say is the most important part of stopping a bird flu pandemic at its source."The world is unprepared," Leavitt said.Many of the poorest countries in Asia lack the resources to launch a formidable effort against a formidable virus. According to the journal Nature, there is a dearth of Tamiflu doses in Cambodia, so if the flu struck, many residents would have no ability to fight it.In Indonesia, according to the journal Nature, many chickens reside in backyard farms spread throughout an idyllic countryside and on thousands of sparsely populated islands, possibly too far from the reach of government.And health experts in Thailand, government officials pride themselves on strong surveillance, but across the Mekong river in Laos, there is barely a public health system.Even in China, the disease surveillance capacity is slow.The result of this mix of capabilities in Asia spells problems for the rest of the world."One just has to look at the current polio, measles and dengue epidemics in Indonesia to realize that the public health system is having trouble coping with preventable diseases," an unnamed outbreak investigator told Nature.The World Health Organization will work with other international organizations to coordinate with countries whose surveillance is, at best, flagging, but an integral part of the plan may also be the most difficult -- asking farmers to part with their birds, their economic and social cohorts for centuries."We must help people accept that the current strain of bird flu challenges a way of life that has been with us for centuries," said U.N. Secretary General Kofi Annan at the Time Global Health Summit last week. "Hard as it will be, we must find ways to structure that coexistence or we will never be able to stop the viruses migrating from animals to us and to our children."Even the U.S., with all its economic power, is unprepared. In this country, as in Cambodia, there is a shortage of Tamiflu, there is no viable vaccine against H5N1 and should bird flu strike humans here, infectious disease experts say the public health system would be crippled."Our hospitals will be overrun," said infectious disease expert Dr. Michael Osterholm. "We'll run out of ventilators, we'll run out of drugs. How are we going to get through that? That's the basic plan we need right now."Despite each country's economic resolve, fighting a foe that cannot be seen, can barely be tracked, and could potentially ravage communities in weeks will be a Herculean task. These are the unique challenges faced when the world must come together to fight a common enemy."In response to each country's crisis, every country must be involved," Annan said. "Bringing all parts of government, civil society and the private sector together, working in partnership to deal with this crisis."Togetherness, in the current world climate, may be the toughest task of all.