1. Cooperation under the Security Dilemma
2. Kenneth N. Waltz ,Theory of International Politics(Reading, Mass. : Addison-Wesley , 1979 ), 5 . See also Stephen Van Evera, “Hypothesis, Laws, and Theories: A User's Guide,” ver. 2.4, rev. April 1991, in Benjamin Frankel,“Security Studies:A Guide to Authors,” ver. 1.4 (Washington, D.c: November 1992).