@Phanaeusdamon from 1970s until early 80s many more Metpol officers (London) were armed with very little training.
This was only stopped after several accidental shootings of people who merely associated with criminal types rather than actually having done crimes.
if routine arming of UK cops did occur again, it would be victory for political extremists who would have successfully rolled back decades of progress (last routinely armed cops in UK were in 1936)