Credible protection requires the guarantor to be stronger than both protected parties combined

Evidence

Suppose P1—whether buyer or seller—feels dissatisfied with M1’s services, say, because he believes that M1 is favoring P2’s interests over his own. Suppose further that no complaint on the part of P1 has had any effect on M1. Three outcomes are then possible. First, if no other mafioso (or state) is available (at least none of comparable strength)—in other words, if M1 has a monopoly on protection—the situation is straightforward: P1 has no alternative because no one else is able to help him. (One condition for supplying credible protection is that P1 and P2, both individually and together, must be weaker than M1; otherwise P1 could take the matter into his own hands.) Suppose, by contrast, that there is competition in the market: another mafia firm (M2), wielding power comparable to that of M1, supplies protection. In this case P1 has the option of enlisting M2’s protection against M1. — Diego Gambetta, The Sicilian Mafia The Business of…, 183

Categorization

• XREF: Directly tests Gambetta/Schelling credible-commitment logic against the Godfather scene’s premise that Don Corleone can back Bonasera’s claim — the Corleone firm’s ‘strength’ relative to both parties is exactly the condition stated here.