70 A. AND OTHERS v. THE UNITED KINGDOM JUDGMENT pp. 34-36, §§ 13-14, Series A no. 3, and Ireland v. the United Kingdom, cited above, §§ 194-96 and 212-13). It must now, therefore, consider whether the United Kingdom’s derogation was valid. (b) Whether the United Kingdom validly derogated from its obligations under Article 5 § 1 of the Convention (i) The Court’s approach 173. The Court reiterates that it falls to each Contracting State, with its responsibility for “the life of [its] nation”, to determine whether that life is threatened by a “public emergency” and, if so, how far it is necessary to go in attempting to overcome the emergency. By reason of their direct and continuous contact with the pressing needs of the moment, the national authorities are in principle better placed than the international judge to decide both on the presence of such an emergency and on the nature and scope of the derogations necessary to avert it. Accordingly, in this matter a wide margin of appreciation should be left to the national authorities. Nonetheless, Contracting Parties do not enjoy an unlimited discretion. It is for the Court to rule whether, inter alia, the States have gone beyond the “extent strictly required by the exigencies” of the crisis. The domestic margin of appreciation is thus accompanied by a European supervision. In exercising this supervision, the Court must give appropriate weight to such relevant factors as the nature of the rights affected by the derogation and the circumstances leading to, and the duration of, the emergency situation (see Ireland v. the United Kingdom, cited above, § 207; Brannigan and McBride v. the United Kingdom, 26 May 1993, § 43, Series A no. 258-B; and Aksoy, cited above, § 68). 174. The object and purpose underlying the Convention, as set out in Article 1, is that the rights and freedoms should be secured by the Contracting State within its jurisdiction. It is fundamental to the machinery of protection established by the Convention that the national systems themselves provide redress for breaches of its provisions, with the Court exercising a supervisory role subject to the principle of subsidiarity (see Z and Others v. the United Kingdom [GC], no. 29392/95, § 103, ECHR 2001-V). Moreover, the domestic courts are part of the “national authorities” to which the Court affords a wide margin of appreciation under Article 15. In the unusual circumstances of the present case, where the highest domestic court has examined the issues relating to the State’s derogation and concluded that there was a public emergency threatening the life of the nation but that the measures taken in response were not strictly required by the exigencies of the situation, the Court considers that it would be justified in reaching a contrary conclusion only if satisfied that the national court had misinterpreted or misapplied Article 15 or the Court’s