That is, if M2 is weaker than M1 in "military" strength, and his inferiority is common knowledge, M2 will not intervene, or if he does, he knows he will lose. Thus, P1 would refrain from asking M2 for protection in the first place, knowing it will do him no good. This situation is effectively equivalent to one in which M 1 has a monopoly.

Diego Gambetta, The Sicilian Mafia The Busi…, loc. 839