Rawls discusses the duty of assistance in the article “The Law of Peoples” and the book The Law of Peoples. The duty is merely mentioned subsequent to the list of seven principles in “Peoples” (CP 541). It is stated as the eighth principle in LP (LP 37).
Rawls distinguishes between ideal and nonideal theory. The former concerns relations between liberal and decent peoples – collectively referred to as “well-ordered peoples” – and the latter concerns relations between such societies and those which are neither liberal nor decent. Nonideal theory is directed towards the long-term goal of an international society comprising liberal and decent peoples (LP 89). The duty of assistance, like principles ive (the right of self-defense) and seven (the duty to observe restrictions in war), applies only in nonideal conditions. This contrasts with Rawls’s account of domestic justice in which strict compliance is assumed in the original position (TJ 125) and the principles selected are applicable only in ideal conditions. Rawls claims that, “Well-ordered peoples have a duty to assist burdened societies” (LP 106), which are lacking in the “political and cultural traditions, the human capital and know-how, and, often, the material and technological resources needed to be well-ordered” (LP 106).