>> The term only applies to nuclear, biological or chemical weapons.
>
> Not anymore.
>
> See 18 USC 2332(a).
>
> http://www.law.cornell.edu/uscode/text/18/2332a
>
> which points to 18 USC 921
>
> http://www.law.cornell.edu/uscode/text/18/921
>
> (a) As used in this chapter-
> [...]
> (4) The term "destructive device" means-
> (A) any explosive, incendiary, or poison gas-
> (i) bomb, [...]
You left out the only relevant bits, Jordan. :)
18 USC 921 merely defines "destructive device", 18 USC 2332(a) defines WMD just as I described.