On World Health Day, the Infectious Diseases Society of America and the HIV Medicine Association appreciate the global leadership of the United States in responding to infectious disease threats that know no boundaries. We urge continued leadership to ensure all people living with HIV have access to life-saving medicines that prevent illness and stop transmission of the virus. Putting an end to the HIV epidemic is theoretically within reach, but can only be achieved by intensified and sustained commitment by our leaders. Similar focus and drive for works extending internationally will also foster better screening for prevention of tuberculosis. With improvements in access and treatment for tuberculosis and HIV, there can be a day when no family, community or country is devastated by these diseases. World health will also benefit by forging partnerships to build capacities for response to infectious diseases when and where they originate. Through ground-breaking initiatives that include the President’s Emergency Plan for AIDS Relief, the National Action Plan for Combating Multidrug-Resistant Tuberculosis, the USAID TB program, and the Global Health Security Agenda, the United States has recognized that public health threats in any part of the world pose common challenges everywhere. Growing rates of antimicrobial resistance now pose as great a danger as any historical epidemic. Substantial and sustained global partnerships are the only way to make for a healthier and safer world. U.S. leadership is critical to advancing these efforts.