Have confidence in force (4,2)
I believe the answer is:
lean on
'have confidence in' is the definition.
(leaning on is a kind of having confidence in)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for lean on that I've seen before include "Put trust in" , "Informally, seek to influence by intimidation" , "Cling to" , "bully" , "Pressurise (someone to do something) (colloq.)" .)