Ignorant peacekeepers need energy to contain a conflict (7)
I believe the answer is:
unaware
'ignorant' is the definition.
(thesaurus)
'peacekeepers need energy to contain a conflict' is the wordplay.
'peacekeepers' becomes 'un'.
'need' says to put letters next to each other.
'energy' becomes 'e' (physics symbol as in E=mca).
'to contain' means one lot of letters goes inside another.
'conflict' becomes 'war' (war is a kind of conflict**).
'un'+'e'='une'
'a'+'war'='awar'
'une' placed around 'awar' is 'UNAWARE'.
(Other definitions for unaware that I've seen before include "Nescient" , "Not conscious of what is going on" , "Ignorant - unenlightened" , "Not cognisant" , "Totally ignorant" .)