Why Britain’s ‘Bobbies’ Have Long Been Unarmed

Tradition, now in question amid terror surge, marks country’s effort at ‘policing by consent’

LONDON—The decision not to arm British police officers was made when Sir Robert Peel, the then home secretary, founded the Metropolitan Police in 1829. Police officers were nicknamed “bobbies” after him, and a conscious effort was made to differentiate them as much as possible from the heavily armed British army, which the public then viewed with considerable hostility.

“From the very beginning, every effort was made to portray the police as a civilian force, as just a bunch of ordinary guys,” said Jim Waddington, a professor...