Mutual interest in addressing an outbreak or an ongoing infectious disease problem may provide the impetus for collaborations with countries who have not historically cooperated with the United States on public health projects, or with countries whose relationship to the United States is uncertain. One example is Hong Kong during the transfer of sovereignty from the United Kingdom to China (see Box 5).

At times, concern about disease outbreaks may be sufficiently strong to allow national antagonisms to be set aside in the interests of disease control. During the outbreak of Marburg hemorrhagic fever in 1998, for example, an international investigative team was permitted to enter a contested part of the Democratic Republic of the Congo. Similarly, an international guinea worm eradication team sponsored by the Carter Center received safe passage in southern Sudan in 1995, due to a specially negotiated cease-fire between the government of Sudan and rebel forces. Moreover, a polio eradication team was allowed to operate in civil war-torn Sri Lanka during two “Days of Peace for National Immunization” that were separated by 30 days of warfare. Three decades earlier, during the height of the Cold War, the United States and the Soviet Union agreed on the need to provide coordinated financial and technical support to the smallpox eradication effort.