Terrible danger that is right for a soldier (9)
I believe the answer is:
grenadier
'soldier' is the definition.
(historical term for a grenade-carrying soldier)
'terrible danger that is right' is the wordplay.
'terrible' is an anagram indicator.
'that is' becomes 'ie' (abbreviation for id est, 'that is' in Latin).
'right' becomes 'r' (common abbreviation).
'danger' anagrammed gives 'grenad'.
'grenad'+'ie'+'r'='GRENADIER'
'for a' is the link.
(Other definitions for grenadier that I've seen before include "A household infantryman" , "Infantryman - in red gear (anag)" , "African flier" , "bomb-thrower" , "Soldier - in red gear (anag)" .)