Nuclear Option THIS!! (CS)

So......... North Korea says it is willing to use a pre-emptive strike, if they deem it necessary (or at the very least, they're whipping out that sort of rhetoric before coming to the nuclear bargaining table).
More likely than not, they're just trying to bolster their position before talks start regarding their nukes, our nukes, everybodies nukes.... But the phrase "pre-emptive strike" is frightening as all hell when even remotely associated with nuclear weapons.
Of course, need I even mention where the modern precedent of pre-emptive strike is coming from?