Endless recceing by peacekeepers around east (9)
I believe the answer is:
unceasing
'endless' is the definition.
(I've seen this in another clue)
'recceing by peacekeepers around east' is the wordplay.
'recceing' becomes 'casing' (as in 'casing the joint' or doing reconnaissance).
'by' says to put letters next to each other.
'peacekeepers' becomes 'UN' (United Nations, peacekeeping organisation).
'around' means one lot of letters goes inside another.
'east' becomes 'e' (synonyms).
'casing' after 'un' is 'uncasing'.
'uncasing' going around 'e' is 'UNCEASING'.
(Other definitions for unceasing that I've seen before include "Never ending" , "Constant" , "Not stopping" , "Continuous" , "Never-ending" .)