For two decades, American-led investment through programs like PEPFAR (The U.S. President’s Emergency Plan for AIDS Relief) has helped slash global AIDS-related deaths to their lowest levels in over 30 years. But this progress is now at serious risk. A sudden and sweeping withdrawal of U.S. foreign aid has triggered what the United Nations is calling a “systemic shock” to HIV response systems around the world.According to a new UNAIDS report, if the funding gap remains unresolved, the world could see more than 4 million additional AIDS-related deaths and 6 million new HIV infections by 2029. The consequences are already visible — health facilities shuttered, supply chains broken, testing and treatment disrupted, and clinics in sub-Saharan Africa forced to halt vital HIV services.In January, President Trump abruptly suspended all foreign aid and took steps to dismantle the U.S. Agency for International Development (USAID). That move wiped out $4 billion in pledged HIV funding for 2025, including the backbone funding for programs in Africa, Asia, and Latin America.Launched in 2003 under President George W. Bush, PEPFAR has been called the largest commitment by any country to fight a single disease. Since its inception, it has supported HIV testing for more than 84 million people and treatment for over 20 million. Countries like Nigeria, where 99.9% of the national HIV prevention budget was supported by PEPFAR, are now facing catastrophic disruption.Andrew Hill, an HIV researcher at the University of Liverpool, criticized the U.S. government's abrupt move: “Any responsible government would have given advance warning so countries could plan,” he said. “Instead, patients were stranded, and clinics closed overnight.”The Domino EffectThe fallout from the funding cut is widespread. UNAIDS has reported large-scale impacts: medical facilities without staff, vital medications running out, and HIV testing and surveillance collapsing in several regions.The U.S. was the main funder of HIV data systems across Africa — from patient records to electronic surveillance systems. With that infrastructure now unsupported, global experts worry that tracking and controlling the spread of HIV is about to get significantly harder.“Without reliable data about how HIV is spreading, it will be incredibly hard to stop it,” said Dr. Chris Beyrer, director of the Global Health Institute at Duke University.What makes this funding crisis even more tragic is the timing. Just as the world reaches the brink of a possible HIV breakthrough, it may be losing the means to distribute it.Gilead’s new injectable drug, Yeztugo, was approved by the U.S. FDA last month. Clinical trials suggest it is 100% effective at preventing HIV when administered twice a year. At a launch event, South Africa’s Health Minister, Dr. Aaron Motsoaledi, emphasized its potential: “We will move mountains and rivers to make sure every adolescent girl who needs it will get it.”Yet many countries may never see the drug. Gilead has promised low-cost generic versions for 120 poorer countries, but has notably excluded most of Latin America — where HIV rates are increasing, even if they are lower overall.Peter Maybarduk, director at Public Citizen, called it a “threshold moment” in the fight against AIDS. But he fears it will be squandered: “We could be ending AIDS. Instead, the U.S. is abandoning the fight.”Sub-Saharan Africa accounts for roughly half of all new HIV infections globally. Even before the U.S. pullback, access to care and medication in the region was fragile and uneven.Dr. Tom Ellman, with Doctors Without Borders in South Africa, put it bluntly: “There’s nothing we can do that will protect these countries from the sudden, vicious withdrawal of support from the U.S.”While some nations have begun building domestic HIV response programs, the gap left by the U.S. is simply too wide. Prevention campaigns are faltering, awareness efforts have stalled, and many community-based initiatives have been forced to shut down or drastically scale back.In 2004, AIDS claimed nearly 2 million lives globally. By 2024, that number had dropped to around 630,000, largely thanks to international funding and collaborative programs. But UNAIDS warns that without renewed support, these hard-won gains could unravel rapidly.Geopolitical shifts, ongoing wars, and climate-related disruptions are already putting pressure on global health cooperation. The loss of the U.S. as a stabilizing force in the HIV response leaves many questioning what’s next.The most vulnerable — young women, children, LGBTQ+ communities, and those in poverty — stand to lose the most.UNAIDS and other global health leaders are urging the international community to step up. Whether through restoring U.S. funding or rallying alternative donors, a coordinated response is essential. Experts are also calling for pharmaceutical companies like Gilead to expand access and reduce costs, ensuring that breakthroughs don’t become tools of inequality.The global AIDS fight is far from over. In fact, this moment may determine whether it's won or lost.If nothing changes, the consequences are clear: millions of lives in the balance, and a public health crisis reborn from neglect.