Last week, cuddly thug and part-time London mayor Boris Johnson committed one of the trademark blunders for which idiotic people seem to delight in forgiving him, by claiming that President Assad's Syrian regime is worse than that of Nazi Germany, on the grounds that "Not even Hitler used chemical weapons, as far as I can remember."
A lot of people have condemned this as thoughtless, and rightly so: for any politician to pontificate about Hitler without keeping the Holocaust foremost in his mind is crass and horrifically insensitive. All the same (and without condoning his fundamental point), I can see from a purely semantic point of view what might have caused Johnson to phrase his statement the way he did.
It seems to me that generally speaking, the conventions of English don't tend to include tools of execution under the category of "weapons". Obviously some execution methods (beheading, firing squad) involve items whose presence in other contexts makes them unambigously weapons, but despite the dictionary definition (which will usually be something along the lines of "Device designed or used to cause harm to a human [or possibly "a living"] being"), I've yet to hear a guillotine or an electric chair described as a "weapon". As far as I can remember, I've never seen crosses included in lists of Roman weapons, either.
So what exactly makes a killing implement a weapon? It isn't use in combat (as Johnson's hasty clarification seems to assume), because a sentence like "Poison was a favourite weapon of assassination" sounds perfectly reasonable. It isn't use by an individual rather than the state, because (to take an extreme example) almost nobody would call the deployment of a nuclear weapon at Hiroshima the responsibilty of the bombardier on the Enola Gay.
Thinking about it, I suspect that what makes the difference is that there's an element of chance in a weapon's operation, arising from the uncontrolled conditions in which it's used. A poisoner's victim may decide they don't fancy the figs today; a sniper may hit a member of the President's security detail by mistake; even an atom bomb may miss its target or fail to go off.
Executions, though -- and all the more so the industrialised mass murder of the Final Solution -- happen under highly controlled conditions, failure is rectified, and death is (barring the occasional miracle) certain. Such killings become a process rather than an act, and English speakers, probably entirely subconsciously, feel that the term "weapon" no longer really applies.
Which is interesting, I reckon.
Linguistics aside, the only real point I have arising from this is that, if we accept methods of execution as weapons, the United States has been using chemical weapons against its own citizens for decades. Are we going to do anything about that?