Forces into united efforts to attain the goal (6)

I believe the answer is:

drives

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'forces' is the definition.
('drive' can be a synonym of 'force')

I don't understand the remainder of the clue.

(Other definitions for drives that I've seen before include "'Impels, guides (6)'" , "Drivers kinds of urges" , "Motors" , "Operates a vehicle" , "Needs must when the devil ..., it's said" .)

I've seen this clue in the Evening Standard.

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