British police carry stab proof vests, batons and tasers or pepper spray. There would also be two of them, most likely, to one of him. They're also trained in handling such situations without killing people, by talking the guy down and defusing the situation, preferably.
The UK police also have fast response armed units; basically a car with guns locked in a safe in the trunk, which drives around a given area. When it's called upon it can be at a crime scene within that area in a matter of minutes.
Frankly, yes we are. Although I suspect that most people would argue that you have that backwards; A sentiment you hear often here is that if the police go armed, then the criminals will all go armed too - most criminals do not arm themselves at the moment, in part because they know that if they aren't armed, they likely won't face armed police. The thinking is that if both sides tool up for a shooting war, then that's exactly what will happen and there will be many more shooting deaths of both criminals and police.
Incidentally, the majority of the police themselves do not want to be armed, see no need to be, and have consistently said so.