Cooperation requires trust in the sense that dependent parties need some degree of assurance that non-dependent parties will not defect: as I have already said, this need not take the form of 'thick' trust, individually based belief, but it must take some form or other. The next step after this is to claim that, in general, people will not trust others enough to bring about cooperation unless their assurance is to some extent well based: that is to say, unless people are also in general motivated, one way or another, not to defect if they are in a nondependent position.

Diego Gambetta, Trust - Making and Breaking…, loc. 178