Affectionate summons to infants to adopt a military vocation (4,2,4)

I believe the answer is:

call to arms

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

'infants to adopt a military vocation' is the definition.
I don't know anything about this answer so I can't judge whether this works.

'affectionate summons to' is the wordplay.
I cannot really understand how this works, but
'summons' could be 'call' (I've seen this in another clue) and 'call' is present in the answer.
'to' is within the answer.
The remaining letters 'arms' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...

Can you help me to learn more?

I've seen this clue in The Irish News.

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.