Tigers have long provoked awe in the human imagination, becoming symbols of untamed nature whose "fearful symmetry," in the words of William Blake, has inspired everything from art to advertising. In the wild, however, tigers are on the verge of disappearing.

Leonardo DiCaprio fixes a camera trap with WWF staff Pradeep Khanal at Nepal's Bardia National Park. [WWF]

A century ago, some 100,000 tigers roamed the wilderness across much of Asia. But 100 years of human overhunting of tigers' prey, such as deer and wild pigs, and of poaching driven by demand for tigers' skins and other body parts has been catastrophic. As few as 3,200 tigers remain, living in only 7 percent of their original natural habitat.

As the Year of the Tiger draws to a close on the Chinese lunar calendar, world leaders are gathering in St. Petersburg later this month for an unprecedented event: a tiger summit hosted by Russian Prime Minister Vladimir Putin, convened for the sole purpose of saving the species from extinction. Heads of government - recognizing that the limited resources devoted to tiger conservation have not slowed deforestation or deterred the criminal syndicates that traffic in wildlife parts - will seek to double the number of tigers in the wild by 2022 (the next Year of the Tiger). The 13 Asian countries that tigers call home have already agreed in principle to this goal.

But good intentions are not enough. The $350 million, five-year Global Tiger Recovery Program these countries are proposing will battle deforestation, poaching and the market for tiger parts. The money will come from both government and private sources. We are personally committed to raising funds to support these efforts. Multilateral agencies such as the World Bank are also on board, funding pre-summit negotiations in Nepal, Thailand and Indonesia.

But there is one country outside Asia whose cooperation is crucial: the United States. Of course, the United States has no wild tigers. Our big cats are animated in films, sell us cereal or stare at us from zoo cages. Why should we care?

Because saving tigers is a compelling and cost-effective means of preserving so much more that is essential to life on Earth. The tiger is what conservationists call an "umbrella" species. By rescuing them, we save everything beneath their ecological umbrella - everything connected to them - including the world's last great forests, whose carbon storage mitigates climate change.

For example, Indonesia's 18 million-acre peat forests, home to the Sumatran tiger, contain 36 percent of the world's tropical carbon stores. So if we protect tigers by stopping deforestation, we also salvage the carbon storage these forests provide. A forest that can't support tigers isn't of much use to us, either.

What can the Obama administration do? The United States has been a leader in tiger conservation, providing critical funding for anti-poaching efforts throughout Asia and using the threat of sanctions to persuade countries such as China and South Korea to ban tiger trade. But the upcoming summit will not succeed without U.S. support - financial and political. Washington must signal its commitment by sending its top diplomat to St. Petersburg: Secretary of State Hillary Rodham Clinton.

Pressing challenges such as the war in Afghanistan and Middle East peace rightly dominate Clinton's attention, but the crime syndicates that dominate the multibillion-dollar wildlife-trafficking industry demand her consideration as well. If Clinton sits beside other heads of government and high-level diplomats from the 13 tiger-range nations in St. Petersburg, the Obama administration will demonstrate global environmental leadership.

Tiger conservation can also happen at home. The United States has nearly twice as many tigers in captivity as there are in the wild worldwide - tigers sleeping in American back yards, in private breeding facilities and at roadside zoos from New York to Texas. We need a federal agency to monitor these tiger "pets" and make sure they don't find their way into the same black market for wildlife products that kills wild tigers around the world. We can close loopholes in the Endangered Species Act and the Animal Welfare Act and give agencies such as the Fish and Wildlife Service and the Department of Agriculture the financial support they need to vigorously enforce animal protection laws.

Wild tigers stand at a crossroads of extinction and survival. The "burning bright" eyes that so inspired Blake will be forever extinguished unless we act now.