Extremely difficult! I think I have only one left, but have no idea.
6d, seems to be anagram of "had nukes" (5,3)
I have ?K?A? D?U with some uncertainty about K.
Thanks, Zozozo, but I actually got it! Guessed the second word, then was able to piece together the first. I think I may have seen the term in a cryptic long ago.