I know this has been mentioned on other threads but I just don't recall what was said. Does the material in a suitcase nuke have a "shelf life"?
I'm trying to remember exactly where I read this (can't, though: The fissionable material itself doesn't have a half-life but I think I read that the trigger does. I think the triggers are also radioactive (tritium?) and take a certain amount of care and maintenance to keep them useable. You can't just plop them in a bunker, then haul them out in 10 years and expect them to work as designed.
LQ