Wars end through interested patrons, not neutral mediators.

Evidence

Fault line wars are ended not by disinterested individuals, groups, or organizations but by interested secondary and tertiary parties who have rallied to the support of their kin and have the capability to negotiate agreements with their counterparts, on the one hand, and to induce their kin to accept those agreements, on the other. While rallying intensifies and prolongs the war, it generally is also a necessary although not sufficient condition for limiting and halting the war. Secondary and tertiary ralliers usually do not want to be transformed into primary level fighters and hence try to keep the war under control. They also have more diversified interests than primary participants, who are exclusively focused on the war, and they are concerned with other issues in their relations with each other. Hence at some point they are likely to see it in their interest to stop the fighting. Because they have rallied behind their kin, they have leverage over their kin. Ralliers thus become restrainers and halters. — Samuel P. Huntington, The Clash of Civilizations and the…, 805

Categorization

• XREF: Connects to Milgrom’s law merchant work — institutions and enforcement work through interested parties with leverage, not through disinterested third parties.
• DEEPTHINKING: A genuinely counterintuitive inversion: the parties that intensify and prolong a war are the same ones structurally equipped to end it — rallying gives ralliers both the incentive and the leverage to halt fighting, which no neutral broker can match.