And let's not pretend that there are circumstances in which the premptive use of nuclear weapons is justified.

I'll be honest, I have not problem with a preemptive nuclear attack on North Korean facilities if it becomes clear that they intend to put nuclear warheads that match the missiles they sell on the open market.  

Imagine a world in which warring African states or even rebel groups have access to nuclear weapons through the world market. Or private military groups like Blackwater.

Nuclear weapons must not be allowed to become an object of sale on the world market.  If they do they will be used.

And once that taboo is broken, you aren't going to put the genie back in the bottle.  Think about chemical weapons, you had prohibitions against their use in international law prior to the first World War, but once they were used on the battlfield their use multiplied.

Imagine the Iran-Iraq war with counterforce nuclear strikes by the Iraqis against Iranian forces massed in the Fao peninsula.  The Iraqis did use chemical weapons.

And remember that nuclear weapons (and the capacity to deliver them to your adversaries homeland) give possesor states a veto on foreign intervention on their territory.

There's one state that would find that incredibly desirable: Saudi Arabia.

All it would take is the possession of a small nuclear force on the order of the Israeli arsenal in order to prevent intervention.  And if Saudi falls to Sunni extremism in the way Iran fell to Khomeini in 1979?  

Would the US, Britain, or France place their cities on the line to defend the Israeli state against a genocidal attack launched by extremist intent on establishing a regional Caliphate?

What happens if the Israelis destroy Mecca? If they turn the Plain of Arafat, all the holy sites rendered radioactive wastelands?  Do you suppose that would end well for Europe or the United States?

And I'll give my consent to any government that does not deny a man a living wage-Billy Bragg