Hadi was one of the founders of the Centre for Strategic and International Studies (CSIS), a think tank founded in 1971, where he served as an executive director and economist.
Soesastro graduated with an aeronautical engineering degree from the Technische Hochschule in Aachen, Germany.
Aside from his studies, Hadi was active in the Indonesian students association, becoming chairman of the West German branch.
Soesastro obtained his doctorate from the Frederick S. Pardee RAND Graduate School in Santa Monica, California.
[1] Within the academic field, Soesastro was an adjunct professor at Columbia University in New York City.