Hail USA, let organise (6)
I believe the answer is:
salute
'hail' is the definition.
(I've seen this before)
'usa let organise' is the wordplay.
'organise' indicates anagramming the letters (I've seen 'organised' mean this).
'usa'+'let'='usalet'
'usalet' is an anagram of 'SALUTE'.
(Other definitions for salute that I've seen before include "Pay tribute to; greet" , "Greet in a friendly way" , "Acknowledge (superior)" , "Bring hand smartly to cap" , "Gunfire, perhaps" .)