Ultrafast Supercomputer To Simulate Nuke Explosion

Just exactly how long does it take to build a nuke from square one? Because if it doesn't take too long why do we need 40+ year stockpiles?

It would take longer to make the arms than it takes for all of your major cities to turn to ash. Nuclear arms aren't a deterrent if you don't have them on hand and ready to go. It's been said that Japan could have nuclear weapons within three months (if they ever chose to build them).

[edit on 27-3-2005 by Seth76]

Maybe we could hold the materials needed for the nukes in stable states so that when the time comes we can assemble them within minutes. Is that possible?

so if/when nukes "expire" they explode? so then one day couldnt they all just unexpectedly explode?