This article’s point of departure is that the national self-determination doctrine remains one of the most paradoxical, contested, but successful doctrines which has largely contributed to the shape of our existing international system of nation-states. It argues that the doctrine which is intended to safeguard peace and human dignity is and always has been at the heart of many conflicts. Starting with the tension between the universality of the national self-determination doctrine and the particularity of the national group whose interests it promotes, the article explores other paradoxes contained within this doctrine. They range from political and legitimacy challenges to the very nation-state it creates, through the violations of human rights contrary to its very meaning, to the fact that national self-determination doctrine, far from being a national issue, is actually an international affair. While not rejecting the doctrine, the paper concludes with the final (ninth) paradox that perhaps the success of this doctrine should not be measured by how many states it can produce, but how it can make the existing states a safe home for more self-differentiating national groups.