Contemporary constitutional orders increasingly function under conditions of persistent structural emergency caused by pandemics, armed conflicts, terrorist threats, and climate disasters. Unlike the classical model of a temporary departure from the normal legal order, emergency measures today are becoming institutionalized and are being transformed into an element of everyday governance, thereby threatening the very core of constitutional legitimacy. Under these conditions, a fundamental contradiction arises: on the one hand, the state must possess the capacity to respond to crises flexibly and promptly; on the other hand, any adaptation must not undermine the principles of the rule of law, the separation of powers, and respect for inalienable human rights. The aim of this study is to identify the constitutional and legal conditions under which adaptation to permanent emergency remains legitimate and does not turn into systemic erosion of the constitutional order. To achieve this aim, the study employs a set of methods: comparative legal analysis of judicial practice in Colombia, South Korea, India, the European Court of Human Rights, and the United States; a normative and doctrinal approach; and institutional and functional analysis. The study identifies three key components of the normative core of the constitution that may not be legitimately restricted even under an officially declared state of emergency: absolute human rights, including the right to life, the prohibition of torture, and the protection of human dignity; institutional guarantees of democratic constitutionalism, including judicial independence, separation of powers, and electoral legitimacy; and the principle of the rule of law, including the predictability of legal regulation, equality before the law, and mandatory judicial review. On the basis of these components, the article formulates operationalizable criteria for distinguishing legitimate adaptation from constitutional erosion. As a constructive result, it proposes a model of constitutional resilience through institutionalized flexibility. This model does not imply a rejection of adaptation; rather, it requires that adaptation be placed within a strict procedural framework: the automatic expiration of emergency measures after a specified period, or sunset clauses; mandatory reasoned renewal of emergency powers by parliament; public assessment of the impact on human rights; and an enhanced proactive role for constitutional courts. Particular importance is attached to the international legal standards of the Convention for the Protection of Human Rights and Fundamental Freedoms and the International Covenant on Civil and Political Rights, which establish insurmountable limits on any derogations from rights.