52 HASSAN v. THE UNITED KINGDOM – JUDGMENT from their obligations under Article 5 in order to detain persons on the basis of the Third and Fourth Geneva Conventions during international armed conflicts. As the Court noted in Banković and Others v. Belgium and Others (dec.) [GC], no. 52207/99, § 62, ECHR 2001-XII, although there have been a number of military missions involving Contracting States acting extra-territorially since their ratification of the Convention, no State has ever made a derogation pursuant to Article 15 of the Convention in respect of these activities. The derogations that have been lodged in respect of Article 5 have concerned additional powers of detention claimed by States to have been rendered necessary as a result of internal conflicts or terrorist threats to the Contracting State (see, for example, Brannigan and McBride v. the United Kingdom, 26 May 1993, Series A no. 258-B; Aksoy v. Turkey, 18 December 1996, Reports of Judgments and Decisions 1996-VI; and A. and Others v. the United Kingdom [GC], no. 3455/05, ECHR 2009; see also paragraphs 40-41 above). Moreover, it would appear that the practice of not lodging derogations under Article 15 of the Convention in respect of detention under the Third and Fourth Geneva Conventions during international armed conflicts is mirrored by State practice in relation to the International Covenant for the Protection of Civil and Political Rights. Similarly, although many States have interned persons pursuant to powers under the Third and Fourth Geneva Conventions in the context of international armed conflicts subsequent to ratifying the Covenant, no State has explicitly derogated under Article 4 of the Covenant in respect of such detention (see paragraph 42 above), even subsequent to the advisory opinions and judgment referred to above, where the International Court of Justice made it clear that States’ obligations under the international human rights instruments to which they were parties continued to apply in situations of international armed conflict (see paragraphs 35-37 above). 102. Turning to the criterion contained in Article 31 § 3(c) of the Vienna Convention (see paragraph 34 above), the Court has made it clear on many occasions that the Convention must be interpreted in harmony with other rules of international law of which it forms part (see paragraph 77 above). This applies no less to international humanitarian law. The four Geneva Conventions of 1949, intended to mitigate the horrors of war, were drafted in parallel to the European Convention on Human Rights and enjoy universal ratification. The provisions in the Third and Fourth Geneva Conventions relating to internment, at issue in the present application, were designed to protect captured combatants and civilians who pose a security threat. The Court has already held that Article 2 of the Convention should “be interpreted in so far as possible in light of the general principles of international law, including the rules of international humanitarian law which play an indispensable and universally-accepted role in mitigating the savagery and inhumanity of armed conflict” (see Varnava and Others v. Turkey [GC], nos. 16064/90, 16065/90, 16066/90, 16068/90, 16069/90,