AbstractSome polities have strong cultural diversity, some of which is territorially based and politically articulated by significant groups that, in the name of nationalism, and self-determination, advance claims for independence. In this article such polities are defined as ‘politically robustly multinational’. If the goal is peace and democracy in one state in such a polity, this article advances theoretical and empirical arguments to show that ideal typical ‘nation-state’ making policies are less appropriate than policies associated with new ideal type I construct called ‘state-nation’. Countries discussed are Spain, Belgium, and Canada and the ‘matched pair’ of successful Tamil political integration via state nation policies in India, and failed Tamil political integration due to nation-state policies in Sri Lanka.