Richard C. Snyder, 81, an expert in foreign policy. Educated at Union College in Schenectady, N.Y., and Columbia University, he began his career as administrative secretary of war and peace studies at the Council on Foreign Relations in New York City. He taught politics at Princeton University from 1946 to 1955 and then became chairman of political science at Northwestern University. From 1965 to 1970, Snyder served as dean and professor of administration and political science at UC Irvine and chaired the political science panel of the California Social Science Study Commission. He ended his career as director of the Mershon Center at Ohio State University. Snyder was the author of "American Foreign Policy," "Roots of Political Behavior" and other books, and served as president of the International Studies Assn. On Tuesday in Scottsdale, Ariz.