I think you might be missing the subtlety in argument I was relaying. The security staff know how to deal with extremist groups. But they were not dealing with

I think you might be missing the subtlety in argument I was relaying. The security staff know how to deal with extremist groups. But they were not dealing with an extremist group in the traditional sense - where the overwhelming majority of the population are in agreement that their actions are wrong e.g. 9/11, Boston Marathon, Orlando nightclub. They were dealing with a group claiming to act on behalf of the leader of one party in a two party system - in other words, a very significant percentage of the population. It wasn't failing to act, but confusion about choosing whether or not to act and to what extent. They were not prepared for a scenario where taking action could genuinely be a trigger for wide scale insurrection, violence and even civil war affecting millions - the trolley problem on steroids. > Or if they were intending to destroy/damage the building beyond windows and doors. They were - pipebombs and molotov cocktails were recovered. But as uncomfortable as it feels, it might not have been as simple as shooting the bad guys.