Peaceniks marching off couple with belligerent gestures (9)

I believe the answer is:

pacifists

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'peaceniks' is the definition.
The definition and answer can be both people as well as being plural nouns.
Maybe there's an association between them I don't understand?

I don't understand the remainder of the clue.

Can you help me to learn more?

(Other definitions for pacifists that I've seen before include "They don't believe in fighting" , "they won't fight" , "Those who reject war as an instrument of policy" , "People refusing to fight" .)

I've seen this clue in the Sydney Morning Herald.

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