[mcv]

Not really a good comparison. Seat belts save lives, guns take it. The fact that a gun is a real threat to the mugger, makes it a threat to you. Because the mugger knows that you might be carrying a gun. I'm pretty sure that muggers and burglars in the US use a lot more deadly force than elsewhere, exactly because of the chance their victim may be armed.

Of course given that muggers expect you might be armed, you might as well be. But I'm still not convinced they actually make you safer; lots of Americans get killed by their own gun.