I seem to recall a recent movie with a similar plot. Only the nuke was found in the middle east desert due to an Israeli plane crash. Thought movie plots followed reality not the other way around.
Broken Arrow?
Wasn't that a Tom Clancy novel?
I vaguely remember a plot where terrorist discover a lost Israel nuke, modify it for there own uses and then detonate it at a US sporting event. Fortunately the yield is lower due to engineering designs.