Receiving his master's degree in public and international affairs, Tomsen spent two years working in the Peace Corps in Nepal.

[8] Tomsen studied Nepali and taught civics and English in a newly founded 80-student college in a Himalayan town in western Nepal.

Tomsen chose to extend his Peace Corps service for six months to be headmaster of a Tibetan refugee school.

After a year of Vietnamese language training in Washington in early 1969, he was assigned to the U.S. Civilian-Military Advisory Organization in South Vietnam, 1969 - 1970.

From 1984 to 1987, he served in the Department of State as office director of India, Nepal, Sri Lanka, Bhutan, and the Maldives.