Even if one could say that such treatment reflects some policy
of the various foreign states involved, or indeed
of the United Kingdom, it goes far beyond any conduct previously recognised as requiring judicial abstention... The critical point in my view is the
nature and seriousness
of the
misconduct alleged in both cases before the Supreme Court, at however high a level it may have been authorised... Sovereign states who without justification and without permitting access to justice detain or mistreat individuals in the course or in relation to their conduct
of foreign relations or affairs have sovereign immunity in foreign domestic courts.