From Americans we rely on defence (6)
I believe the answer is:
answer
'defence' is the definition.
(thesaurus)
'from americans we rely' is the wordplay.
'from' says the answer is hidden in the clue.
'ANSWER' is hidden within 'americans we rely'.
'on' is the link.
(Other definitions for answer that I've seen before include "Reply or solution" , "Response - solution" , "'A soft . . . . . . turneth away wrath'" , "fit" , "Retort" .)