Long-term rivalries between unequal powers are common, so rivalry need not imply parity.

Evidence

When analyzing “strategic rivalry” Thompson (2001) spends most of the concept theory section discussing exactly this problem. The question is whether we should conceptualize rivalries as only between relatively equal powers or leave the question open. Diehl and Goertz (2000; Klein, Goertz, and Diehl 2004) have shown that this is problematic because in fact one can easily find long-term asymmetric rivalries. Thompson himself realizes that there is a problem because when he gets to data collection he has to decide what to do with these cases (normally he includes them). Here is a case where one would not want to build power symmetry into the rivalry concept, but leave the issue open for further empirical and causal examination. — Gary Goertz, Social Science Concepts, 458

Categorization

• XREF: Connects to the international-relations rivalry literature (Thompson, Diehl, Goertz) and to the general point that inequality is not a barrier to sustained adversarial relations.