On December 28, 1973, I watched President Richard Nixon sign into law the Endangered Species Act.

It was one of my proudest moments in Congress. For thirty years the act has been protecting our environment and species on the verge of extinction.

Today conservationists and supporters look at the Endangered Species Act and call it visionary, while developers and critics refer to it in four–letter terms not fit for print. I disagree with both characterizations.

To me, the act was, and remains, common sense. Like many of the cornerstone environmental laws we put in place during the early 1970s, the Endangered Species Act was passed as a nonpartisan, consensus undertaking: the House of Representatives voted 391㪤 and the Senate 92ל.

The act remains a prime example of our nation’s long, proud tradition of respect for our wildlife and natural resources. In enacting it, the United States sent a strong message to the world by putting our nation on the forefront of protecting wildlife in an effort to make our own habitat a bit better. Ours was the first nation to say that only natural extinction is part of the natural order and that extinction caused by human neglect and interference should be prevented to the maximum extent possible.

Most important, the Endangered Species Act is a dynamic and flexible law that continues to work. To date, fourteen species have been recovered, including the peregrine falcon and the gray whale. This occurred notwithstanding the fact that a species is not typically listed until its population is extremely depleted. Another measure of success is the fact that 41 percent of the listed species have improved or stabilized their population.

Despite the success of the Endangered Species Act and its bipartisan origins, the law begins its fourth decade under a quiet, yet dangerous assault. The Bush administration and the Republican leadership in Congress have undertaken a sustained effort to roll back the act and create vast carve–outs for the Defense Department and numerous special interests.

In the last decade we have seen the U.S. military at its most effective. Our armed forces have won two major wars in Iraq, toppled the Taliban in Afghanistan, stopped a civil war in Yugoslavia and prevented genocide in Kosovo. All these missions were trained for with the Endangered Species Act intact. Yet now the administration appears to be saying that desert tortoise preservation is a threat to our national security and that this nation’s conservation laws weaken our ability to wage the war on terror.

This is an outrageous claim that not only gives short shrift to the abilities of our military personnel but also completely ignores the fact that the act already contains exemptions for national security. Under the act, should the secretary of defense request a waiver for national security, a committee—comprising a number of cabinet secretaries, agency directors and representatives of the states—is required to not only review the request but also grant it.

Unfortunately, the Bush administration never attempted to take advantage of the waiver process we very purposefully built into the Endangered Species Act. Instead, the administration quietly stuck a rider onto this year’s defense authorization bill that essentially carved the Defense Department and its millions of acres of land out of the act. The rider allows the military a much lower standard than the current law and, ultimately, will likely shift the burden of providing for the recovery of endangered species to private landowners.

And efforts to narrow the law have not been confined solely to domestic exemptions for the military. The administration recently announced an effort to roll back the act’s prohibition on importing endangered species from abroad. This is simply wrong.

The act’s prohibition on importing endangered species helped prevent the extinction of the African elephant, which was being decimated out of greed for its ivory tusks, and the act has served to protect other magnificent animals, including the rhinoceros, the Bengal tiger and the humpback whale.

Because of these assaults on the Endangered Species Act, last month I joined with other legislators in signing a pledge to uphold the act for another thirty years to ensure that it will continue to protect our land, wildlife and natural resources for our children and grandchildren to enjoy. I hope that other members of Congress, regardless of party affiliation, will also lend themselves to this fight to keep the Endangered Species Act from becoming endangered.

The Endangered Species Act has been successful for thirty years. Without it, there might not be a single bald eagle or peregrine falcon in our skies, no manatees or cutthroat trout in our waters, no gray wolves or grizzly bears in our forests. And the Endangered Species Act preserved our natural heritage during a time in which the U.S. economy grew at record rates. This is critically important to me as an avid hunter and sportsman who represents a congressional district primarily dependent on development and manufacturing growth for its well–being.

As we close out the first thirty years of the Endangered Species Act and open the door to the next, our goal should be to maintain the integrity of the law. The act has all the tools we need to protect our natural environment while promoting our national economy—and that’s something well worth preserving.

Michigan Democrat John D. Dingell is the senior member of the U.S. House of Representatives and the author of the Endangered Species Act.