Secretary of State V. Rehman  1 AC 153
Immigration law: Terrorism
In determining whether a person is a treat to nation security a global approach should be adopted to consider whether a person is a treat to national security.
The Appellant who was investigated for acts of terrorism appealed against the decision of the Court of Appeal that conduct of the appellant outside that UK could be investigated to determine whether deportation was 'conducive to public good'.
The House of Lords held that threats to national security also means threats against other states and not limited to direct threat to the UK. For the protection of national security the Secretary of State is entitled to determine real possibility to national security and this does not have to be proved against.