This article examinizes the boundaries of human rights in the context of 21st century global diplomacy, focusing on the dialogue between freedoms and obligations. It analyzes how tensions between ethical universalism and global realpolitik have produced new challenges for the protection and promotion of fundamental rights, especially in humanitarian crises, migration policy and multilateral diplomacy. The study follows an interdisciplinary theoretical-empirical approach, combining conceptual analysis with concrete cases (Kosovo, Syria, Ukraine, Rwanda), as well as a comparative examination of diplomatic discourse and documentation of international institutions. Primary and secondary sources are used to identify patterns of balance between freedoms and duties in diplomacy. The main findings indicate a shift in global diplomacy from universalism to selective pragmatism. Human rights are often used as a diplomatic instrument with double standards. Meanwhile, the concept of duty remains undervalued in Western discourse, while other cultural approaches offer more balanced models. This article argues that to maintain the legitimacy and effectiveness of international human rights diplomacy, an ethical reconceptualization of the relationship between freedom and responsibility is necessary. It suggests the creation of an intercultural and international ethics that goes beyond technical standards and includes a common code of duties, in addition to rights. This approach can help increase diplomatic coherence and strengthen international consensus on global justice.