In a dyad, the less democratic state sets the rules of engagement.

Evidence

In the first place, the minimum measure does outperform all others in revealing the assumed causal relationship between democracy and militarized conflict. And secondly, the overall pattern of results is consistent with our conception of substitutability, with the performance of measures inversely related to their degree of substitutability. … The weakest-link logic asserts that democratic constraints are strictly nonsubstitutable and this is exactly what our analysis has confirmed, at least in the theoretical context of the liberal peace. In practical terms this means that for any pair of states it is the less democratic one that establishes the norms and procedures governing the interactions between them. If the pair is democratic then democratic norms prevail, but if one or both is not democratic then realist power politics govern their interactions. — Gary Goertz, Social Science Concepts, 937

Categorization

• DEEPTHINKING: Generalizes to any relational system built on a binding constraint: a transaction, a marriage, an alliance runs on its weakest party’s terms, so the average is the wrong summary statistic for the pair.
• SEED: Angle: ‘The weakest link governs the pair’ — apply the minimum-not-mean rule to supply chains, couples therapy, cybersecurity, and treaty design.