Sorry - I am new at this and assumed that only Guardian solvers would respond!
3dn: Perhaps contacts the French about nuclear antagonists (6) I have ?e?s?s
1dn: Like Knox, perhaps, pair find the Ultimate Answer (5-3)
Lenses looks OK. French the = le, NS = Nuclear ship, and I am guessing the antagonists are bridge players East and South? Not 100% sure of my reasoning, though!
After further thought, we reckoned "les" for "the" French, including "n" for nuclear and "se" for South and East at bridge.
Thanks for your welcome, Bernie.