Thomas David Zweifel is a Swiss-American university professor and author known for his theories Strategy-in-Action, the Global Leader Pyramid, and the Matterhorn of Masterful Listening.

[1][2] From 1985 to 1997, Zweifel worked for the non-governmental organization The Hunger Project on the roster of the United Nations Economic and Social Council (ECOSOC).

As its Director of Global Operations (from 1992 to 1997), he lived in various European countries as well as in Japan, India, and the United States.

In 1996, Zweifel earned a master's degree from the School of International and Public Affairs at Columbia University.

[4] In 2001, he earned a PhD in International Political Economy from New York University with a thesis on the democratic deficiencies of the European Union, particularly in the regulation of corporate mergers.