One of my 2013 predictions — coming soon! — is that rifles will trail knives as murder weapons of choice in the coming year as they have in the most recent five-year period for which statistics are available. Magical thinking underlies the calls for gun control in the wake of the slaughter of the innocents at the Sandy Hook school, but a relentless logic is at work in this anecdote of modern life in the Britain formerly known as Great: A disabled caravanner who kept a penknife in his glove compartment to use on picnics has blasted the authorities after...