After earning his Ph.D. in 1966, Wollan was an assistant professor of physics at Virginia Polytechnic Institute where he did research on electron and nuclear magnetic resonance of rare earth ionic crystals.
[1][2] In 1974, he went to the U.S. Arms Control and Disarmament Agency (ACDA) as a physical science officer, and served on U.S. delegations to SALT II and START negotiations.
He spent a great deal of time in Geneva on negotiations in those years, and met his second wife, Barbara, there.
In 1989, he was made chief of the Theater and Strategic Defense Division of ACDA, the office responsible for the ABM Treaty and related issues.
He evolved the role of his office to include development of shared early warning protocols with many foreign countries and the exploration of international "rules of the road" for space operations.