Unable to decide whether to join the Navy (4)

I believe the answer is:

torn

I'm a little stuck... Click here to teach me more about this clue!

'unable to decide' is the definition.
(I've seen this in another clue)

'to join the navy' is the wordplay.
'join' means one lot of letters go next to another.
'the navy' becomes 'RN' (abbreviation for Royal Navy).
'to'+'rn'='TORN'

'whether' acts as a link.
This may not be right. It may belong to another bit of the clue.

Can you help me to learn more?

(Other definitions for torn that I've seen before include "Dance wear" , "Removed forcibly" , "Ripped - undecided" , "'-- Curtain', 1966 Hitchcock film" , "Ragged" .)

I've seen this clue in the Evening Standard.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.