Who Must Prevent the Next Reich? Extreme Injustice, Relational Realism and Global Legal Responsibility

A constituent assembly elected with majority support strips native-born Brazilians defined by descent of their nationality and authorizes their expulsion. The research asks who may demand which conduct from which State, on what legal basis and before which irreversible moment. It argues that constitutional replacement extinguishes neither the State's international obligations nor the requirement to justify the deprivation to each person affected; that relational position identifies and grades the loss but does not by itself ground the obligation; and that third-party responsibility does not follow the gravity of the harm, depending instead on a legal link, on effective control over the means of protection and on a demonstrated source. Comparison with existing law, including the European Pact on Migration and Asylum, applicable since June 2026, and with Monica Hakimi's theory of specific protective duties shows that the link-based distribution of duties already has precedents. The residual contribution is procedural and temporal: two distinct treaty-based procedures are proposed, one for the timely review of data transfers capable of locating persecuted persons and another for urgent admission decisions tied to a last-resort allocation rule, both triggerable by those affected and subject to review. The research, theoretical and legal-doctrinal, tests each proposition through controlled variations and states the conditions under which it would fail. Author's English translation of the Portuguese original, "Quem deve impedir o próximo Reich? Injustiça extrema, realismo relacional e responsabilidade jurídica global".