As to who can commit treason, it depends on the ancient notion of allegiance. As such, all British nationals (but not other Commonwealth citizens) owe allegiance to the Queen in right of the United Kingdom wherever they may be, as do Commonwealth citizens and aliens present in the United Kingdom at the time of the treasonable act (except diplomats and foreign invading forces), those who hold a British passport however obtained, and aliens who – having lived in Britain and gone abroad again – have left behind family and belongings.