It is a week since Khalid Masood ploughed his car into pedestrians on Westminster Bridge, killing three people, before fatally stabbing PC Keith Palmer just inside the Parliamentary Estate. London has seen it all before.
By Marcus TannerThe last decade has seen the security concerns of the Balkans dwarfed in comparison to Afghanistan and Iraq, although progress has been made in the region there are still deep divisions.
Since he was charged with terrorism offences, commentators have argued that Breivik was insane or deranged. Yet, like individuals inspired by al-Qaida, Breivik carried out attacks to provide publicity for a political agenda. Only Breivik's meticulous planning and ruthlessness sets him apart from other violent extremist nationalists.