In the past five months, we have witnessed an abrupt, and unprecedented disruption to the institutions, agreements, and norms that have supported global public health for decades. The United States has withdrawn from the World Health Organization, effectively dismantled USAID, and cut 83% of its humanitarian programs. The U.S. is not alone, other nations are scaling back critical development and assistance funding. At the same time, we face mounting and increasingly complex threats to global health. Historic rainfall is driving outbreaks of infectious disease; extreme heat now claims nearly half a million lives each year and pushes the limits of human survivability; and more frequent, extreme weather is destroying infrastructure and disrupting supply chains, leaving communities without access to essential care.