This book explores the progressive development of international law in the post-Cold War period, tracing the emergence of a new understanding of external self-determination that includes remedial secession. This evolution challenges traditional interpretations of the principles of sovereignty and territorial integrity. Through the prism of remedial self-determination, it analyses the development of new norms, demonstrating how secessionist acts have altered state perceptions on secession. By focusing on state practice in the context of post-Cold War self-determination disputes - Timor-Leste, Kosovo, and Iraqi Kurdistan - the analysis illustrates the conditions under which remedial secession has gradually emerged as a viable outcome for addressing secessionist conflicts.