It is generally recognized today that the United States has a need to contri­ bute to the improvement of health throughout the world. The need stems from the interrelationships that exist between the health of Americans and the health status of the rest of the people on "Spaceship Earth." Disease does not respect national boundaries, and the frequency of travel and trade between countries increases each year. It further relates to the opportunities found in international settings to help solve health problems more effec­ tively and efficiently. This includes the unique human resources that are found throughout the world as well as certain natural ecological conditions that cannot be duplicated in the United States. The United States also has a responsibility to contribute to improved health status. Our tradition of humanitarianism alone supports such a re­ sponsibility, but our comparative wealth of technical and financial re­ sources dictates a requirement to participate. Modern political realities de­ fine relationships between developed and developing countries that will not allow us to isolate ourselves from the compelling health needs of a majority of the world's population.