Here's the thing, it's not even from a paper, it's from a slideshow with a discussion of International Relations. The slide before it reads:

"Neoliberal approach:

Concedes to realism several important assumptions

But states achieve cooperation fairly often because it is in their interest to do so.

Reciprocity helps international cooperation emerge—norms and rules are enforced without central authority.

Reciprocity also contains danger of runaway hostility—tit-for-tat punishments—but norms mediate states' interactions."