Sick is a retired captain in the U.S. Navy(equal to a full bird colonel in the US Army)Captain . He received a B.A. from Kansas University in 1957, and later earned a Master of Science degree at George Washington University (1970), followed by a PhD in political science at Columbia University (1973).

Sick served on the staff of the National Security Council under President Carter, and was the principal White House aide for Persian Gulf affairs from 1976 to 1981, a period which included the Iranian revolution and the hostage crisis.

After leaving government service, Sick served as Deputy Director for International Affairs at the Ford Foundation from 1982 to 1987, and is the executive director of the Gulf/2000 Project at Columbia University (1993—present). He is currently an adjunct professor of International Affairs at Columbia's School of International & Public Affairs, and a senior research scholar at SIPA's Middle East Institute. In addition to his professional duties, he sits on the board of directors of Human Rights Watch, and serves as founding chair of the Advisory Committee of Human Rights Watch/Middle East.