The article presentsthe historical and legal aspects ofthe Ukrainian crisis inthe context ofthe development ofmodern international law. The events in Ukraine in 2014–2024 actualized many institutions of modern international law: the hierarchy of principles of territorial integrity of states and the right of peoples to self-determination, the problem of secession and the role of referendums in the creation of new independent states, the issue of their recognition in the international arena and the protection of compatriots abroad. The weak codification of the norms of law, their different interpretations and the lack of ready-made solutions to the challenges of our time indicate that modern international law represents a kind of balance, the balance of power in international relations, which can change depending on various factors. The author’s analysis shows that the new realities of the modern world are making adjustments in the interpretation of the issues of secession, the role and recognition of referendums for independence. The concept of “Separation in the name of salvation” is one of the modern manifestations of the relationship between the principle of universal respect for human rights and the principle of the right of peoples to self-determination.