Canadian authorities knew that this overweening show of paramilitary hubris would draw the violent dregs of nihilism from around the world. Previous summits offered stark and certain warnings. Given that, the attempt to provide security for the city and its inhabitants has been a sad and disturbing failure.
What is the critical lesson?
Don’t even try to hold international political conferences with this kind of explosive ideological charge in the heart of a major urban centre. You sacrifice either the safety of the politicians or the safety of the city.