The tragedies of our world—mass shootings, terrorist attacks, war—dominate the daily news and leave a sense of bleakness. But more quietly, recent events in global health policy provide a reason for optimism.

Several countries recently announced historic pledges to the Global Fund to Fight AIDS, Tuberculosis and Malaria for its next three-year funding cycle, 2014 through 2016. France has pledged $1.4 billion, the Nordic countries have collectively pledged $750 million, and the U.K. has pledged $1.6 billion.

The Global Fund to Fight AIDS, Tuberculosis and Malaria is the main multilateral funder in global health. It successfully channels 82 percent of the financing to fight TB, 50 percent of financing to combat malaria, and 21 percent of financing for HIV/AIDS. The goal of the Global Fund is to get all three of these deadly diseases under control, removing them as threats to public health. It’s an ambitious goal, but also an attainable one.

Take HIV, for example: When HIV-infected individuals are treated with antiretroviral therapy, the risk of transmitting the virus to an uninfected person decreases by 96 percent. In other words, treatment is prevention. What about TB? When TB screening and treatment are available, TB is much less likely to develop drug resistance. We can currently treat a case of TB with drugs that cost about $30, but it costs 100 times as much to treat a case of multi-drug-resistant TB.

The Global Fund has been a model of effective foreign assistance. Recipient countries develop their own proposals, an independent review panel evaluates them, and all results are tracked and published publically. With Global Fund assistance, countries have doubled the number of people on HIV treatment over the past five years to nearly 10 million. They have also doubled the number of cases of TB that have been detected and treated, reaching 11 million people. Over 340 million insecticide-treated bed nets have been distributed and 330 million cases of malaria have been treated, helping cut deaths due to malaria in Africa by one-third over the past decade.

We are at a historical tipping point in fighting these three diseases, but the gains are fragile. If we take our foot off the gas now, we can easily lose the window of opportunity.

Every three years, donors meet to make a three-year financial pledge to the Global Fund. The U.S. just announced that it would serve as the host of the Fourth Replenishment conference on December 3, 2013. This is a very welcome sign of support. However, it is no guarantee that the U.S. will make a bold funding pledge. To allow the Global Fund to reach its $15 billion target, the U.S. needs to pledge $5 billion for 2014-2016. For every $1 the U.S. donates, the Global Fund leverages $2 from other donors.

Considering our era of hyper-polarized politics and our recent government shutdown, it may surprise you that this is a topic on which Republicans and Democrats have been able to agree. Earlier this year, both the House of Representatives and the Senate allocated $1.65 billion to the Global Fund in their respective FY 2014 State and Foreign Operations appropriations bills. Funding for international health and development programs accounts for less than one percent of the U.S. budget, and yet it leads to tremendous results in human survival, economic development, and global security.

Let us urge our members of Congress and President Obama to stand in support of the Global Fund and pledge $5 billion at the December pledging conference. Investing now can lead to truly amazing results.

Nina A. Woolley is a first-year student at Harvard Medical School. She is a volunteer with the American Medical Student Association’s AIDS Advocacy Network.