Last month, the U.S. government stood on the sidelines as much of the world united for the final push to eradicate polio. Now, Congress has a chance to put us back on track.

At the Global Vaccine Summit on April 25 in Abu Dhabi, world leaders committed $4 billion to the global effort to end this devastating disease. The unprecedented gathering — convened by the crown prince of Abu Dhabi, United Nations Secretary-General Ban Ki-moon and Bill Gates — included longtime nation-donors such as the United Kingdom, Norway and Germany and new supporters such as the Islamic Development Bank and New York Mayor Michael Bloomberg. Together they are investing in a new plan to get us to the finish line and achieve a polio-free world by 2018.

Since 1988, the number of new polio cases worldwide has plummeted from 350,000 cases to 223 last year. With only 26 so far in 2013, we have the smallest number of cases in the fewest countries ever, creating a dramatic opportunity for eradication. India, for example, was recently declared polio-free following an intensive effort to root out the disease.

Yet one important piece of the puzzle is currently missing: the United States.

The absence of a new commitment from the U.S. government is troubling and surprising, given our tradition of leading the polio eradication effort. Our leadership began more than half a century ago, when President Franklin D. Roosevelt championed a grass-roots movement against the insidious disease. He founded the March of Dimes, which in turn supported the research that led Jonas Salk and Albert Sabin to develop their life-saving vaccines. Millions upon millions of Americans united to end polio in what is considered to be the largest and most successful public health campaign in our nation’s history.

After polio was eliminated in the United States, we marshaled resources for global eradication. The American private sector has made vital contributions, led by Illinois-based Rotary International and the Bill and Melinda Gates Foundation. And until now, the U.S. government has been the world’s biggest sponsor of this effort, spending more than $2 billion since the 1980s, with the Centers for Disease Control and Prevention and the U.S. Agency for International Development providing vital assistance to help countries become polio-free.

Members of Congress have played a central role in American leadership of this cause and many are longstanding advocates for eradication. In fact, the Rotary International recently recognized five members as Polio Eradication Champions: Sens. Mazie K. Hirono, D-Hawaii, and Johnny Isakson, R-Ga.; and Reps. Jack Kingston, R-Ga., Jim McDermott, D-Wash., and James P. Moran, D-Va.

U.S. support has brought us within reach of a polio-free world. Now, global leaders are uniting around a new plan that is our best chance to defeat the disease. Implementing the plan, which was recently endorsed by more than 450 leading scientists and experts in 80 countries, would make polio only the second infectious disease in history (smallpox being the first) to be wiped from the face of the earth.

The $5.5 billion plan pursues multiple avenues to end polio by 2018, including simultaneously interrupting all polio virus transmission, strengthening routine immunization and ensuring that eradication leaves a legacy to benefit other public health priorities. The plan’s comprehensive approach is different from past endeavors, and relies on upfront assurances of full funding to confidently make the long-term investments that will be necessary to end the disease.

Despite new commitments from around the world, including major multi-year commitments from several countries, the present plan still faces a $1.5 billion funding gap that dramatically compromises its chances of success. The U.S. government must now step up, as it has so generously in the past, by making a multi-year commitment to polio eradication in the same way it has for other critical global health priorities, including the GAVI Alliance for children’s vaccines and the Global Fund to Fight AIDS, Tuberculosis and Malaria. President Barack Obama’s fiscal 2014 budget includes a $15 million increase for polio, which is a significant step in the right direction. But that won’t be enough to take us to the end.

In these times of budget austerity, it is more important than ever for Congress to prioritize polio and go beyond the president’s proposal. Eradication is a worthwhile investment that is expected to generate $40 billion to $50 billion in benefits, mostly to the poorest countries. Conversely, if we fail to eradicate polio, we will continue paying the price of the disease indefinitely. The cost of maintaining current vaccination campaigns — $1 billion per year worldwide — is simply not sustainable.

As Bill Gates noted: “Successful implementation of the plan requires a significant but time-limited investment that will deliver a polio-free world and pay dividends for future generations.”

Working together, the global community can provide a great gift to humanity: generations of polio-free children. Congress and the American people have always been on the front lines of this struggle. We must continue our commitment until the job is done.

David Oshinsky is the Pulitzer Prize-winning author of “Polio: An American Story,” directs the Division of Medical Humanities at the NYU-Langone Medical Center.