Consider idiots surrounding head of state (6)
I believe the answer is:
assess
'consider' is the definition.
(thesaurus)
'idiots surrounding head of state' is the wordplay.
'idiots' becomes 'asses' (I've seen this before).
'surrounding' is an insertion indicator.
'head of' says to take the initial letters.
The first letter of 'state' is 's'.
'asses' going around 's' is 'ASSESS'.
(Other definitions for assess that I've seen before include "Estimate, decide the value of" , "Make estimate or appraisal of" , "Evaluate worth" , "Gauge, evaluate" , "Evaluate, estimate" .)