Professor Gassama has been heavily involved in issues surrounding human rights, foreign policy, and international economic development. These issues led him to recruit and train observers of elections in Haiti and South Africa, including South Africa's first all-race democratic election. In some cases, he served as an observer himself. Afterward, he supervised reports from the governmental agencies involved in the elections. Gassama has also worked as a staff attorney for the Legal Action Center in New York, representing clients on employment discrimination issues.
From 1985 to 1990, Gassama worked on human rights, foreign policy, and international economic development issues for TransAfrica, the African American lobby for Africa and the Caribbean. In 1994 Gassama coordinated the recruitment, training, and deployment of U.S. based nongovernmental observers participating in South Africa's first all-race democratic election. Gassama supervised the preparation of reports on the work of the South African Independent Electoral Commission and participated in two election-observer delegations composed of American and African lawyers.
Gassama's academic interest focuses on problems of international order; the changing role of international institutions in the post Cold War era; and the interrelationships among human rights, environmental degradation, and economic development.