A foreign chap resolved to stop youths making catapults? (6,4)
I believe the answer is:
launch pads
'catapults?' is the definition.
(a launch pad catapults something away)
'a foreign chap resolved to stop youths' is the wordplay.
'a foreign' becomes 'un' ('a' translated into French).
'resolved' indicates anagramming the letters.
'to stop' indicates putting letters inside (stopping can mean blocking a gap).
'youths' becomes 'lads' (lad means a boy or young man).
'chap' anagrammed gives 'chpa'.
'un'+'chpa'='unchpa'
'unchpa' inserted within 'lads' is 'LAUNCH PADS'.
'making' acts as a link.
(Another definition for launch pads that I've seen is " platforms".)