Let's not start a war over this one. We think most people probably know the correct pronunciation of "nuclear", even if some US Presidents don't. So far Eisenhower, Carter, Clinton and the second Bush have been recorded getting this one wrong, which is a concern if they really do have the big red button on their desk. Fingers crossed they'll never be tempted enough to actually press it!
"Noo-cu-lar" or "new-kill-er" are both common mispronunciations of the word, which isn't exclusive to use in weaponry, and actually just means "related to the nucleus". Once upon a time "nuclear family" used to mean immediate family, for example parents, children and siblings. Nowadays if you heard that phrase you'd probably assume they had superpowers, but the right way to pronounce "nuclear" is "new-clear". Clear enough for you?