Portugal involved in distribution of opiates -- how suitable! (8)
I believe the answer is:
apposite
'suitable' is the definition.
(thesaurus)
'portugal involved in distribution of opiates' is the wordplay.
'portugal' becomes 'p'.
'involved in' means one lot of letters goes inside another.
'distribution of' indicates an anagram.
'opiates' is an anagram of 'aposite'.
'p' put into 'aposite' is 'APPOSITE'.
'how' acts as a link.
(Other definitions for apposite that I've seen before include "Germane" , "Of a remark, appropriate for the occasion (8)" , "Meet" , "A pit pose could be to the purpose" , "Suitable, relevant" .)