Nuclear force? (5)

I believe the answer is:

cadre

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'nuclear force?' is the definition.
The answer and definition can be both groups as well as being singular nouns.
Maybe you can see a link between them that I can't see?

This is the entire clue.

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(Other definitions for cadre that I've seen before include "Political group" , "activist group" , "Group of key people" , "Raced around with army unit" , "Nucleus of trained fighters" .)

I've seen this clue in The Globe and Mail.

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