Thank you so much Tim for putting it so well. You fought for our country and I was a Police Office for over 30 years with 18 of it as a Tactical Firearms Unit Officer. We both therefor have some knowledge of terrorism in the U.K.
Canvasback, I can't really imagine any Police Officer running away. In fact one British Transport Officer tackled one of the terrorists armed with nothing more than his truncheon; he is now in hospital with multiple stab wounds. Another off duty Officer physically tackled one and he too is in the same situation plus three other unarmed Officers hospitalised who also stepped in.
British Police Officers are not routinely armed. All forces have some sort of armed response unit on call at all times. I would be on normal unarmed duty until required. I carried my kit in the vehicle and would either have to collect a firearm or have one brought to me. Usually used in pre-planned operations or when the mess hit the fan or after the armed response unit had contained the situation. London is a large force in a small area and can afford to have an armed tactical unit on standby at all times and I suspect most larger city's have the same. British armed Officers are all volunteers who are only accepted for training if they have a clean disciplinary record are known to have a stable temprement and can work under stress. A typical course starts with about 16 applicants and ends with 3 or 4 as the course is so intense. Extremely high standards of accuracy with each type of firearm is required and it's not just a matter of standing still and putting the shots in the bull in your own time. That standard has to be maintained; missing is not an option and you have to re-qualify on each weapon every three months. A typical year for me for training would consist of four days with handgun, four days tactics with handgun, four days pure tactical training, four days with shotgun, four days with H&K MP5, four days with light sniping rifle for urban use, four days with heavy sniper rifle for rural use, four days diplomatic protection training, one week of sniper training in tactics, one day with use of baton rounds and CS munitions and one day destruction of animal training. These would each be spread out on a three monthly rotation and the need to qualify each time on each weapon. The only weapon I was not qualified to use was the Styer AUG .223 as that was what was carried by the armed response units. Most Officers are not armed but those who are can be trusted to do the job pretty well. Lagopus.....