62 A. AND OTHERS v. THE UNITED KINGDOM JUDGMENT was not necessarily directed at the United Kingdom but instead at other nations to which it was allied. 145. In any event, the enactment of Part 4 of the 2001 Act and the power contained therein to detain foreign nationals indeterminately without charge was not “strictly required by the exigencies of the situation”, as the House of Lords found. The impugned measures were not rationally connected to the need to prevent a terrorist attack on the United Kingdom and they involved unjustifiable discrimination on grounds of nationality. SIAC – which saw both the closed and open material on the point – concluded that there was ample evidence that British citizens posed a very significant threat. There could be no grounds for holding that the fundamental right of liberty was less important for a non-national than a national. Aliens enjoyed a right of equal treatment outside the context of immigration and political activity, as a matter of well-established domestic, Convention and public international law. There were other, less intrusive, measures which could have been used to address the threat: for example, the use of control orders as created by the Prevention of Terrorism Act 2005; the creation of additional criminal offences to permit for the prosecution of individuals engaged in preparatory terrorist activity; or the lifting of the ban on the use of material obtained by the interception of communications in criminal proceedings. 2. The Government 146. The Government contended that States have a fundamental right under international law to control the entry, residence and expulsion of aliens. Clear language would be required to justify the conclusion that the Contracting States intended through the Convention to give up their ability to protect themselves against a risk to national security created by a nonnational. As a matter of ordinary language, “action being taken with a view to deportation” covered the situation where a Contracting State wished to deport an alien, actively kept that possibility under review and only refrained from doing so because of contingent, extraneous circumstances. In Chahal v. the United Kingdom (15 November 1996, Reports 1996-V), a period of detention of over six years, including over three years where the applicant could not be removed because of an interim measure requested by the Commission, was held to be acceptable under Article 5 § 1 (f). 147. Each applicant was served a notice of intention to deport at the same time as he was certified under the 2001 Act. The second and fourth applicants elected to go to Morocco and France respectively, and were allowed to leave the United Kingdom as soon as could be arranged, so no issue could arise under Article 5 § 1 in their respect. The possibility of deporting the other applicants was kept under active review throughout the period of their detention. This involved monitoring the situation in their countries of origin. Further, from the end of 2003 onwards the Government