Smart maiden worked out way to decrease international danger maybe? (11)
I believe the answer is:
disarmament
'way to decrease international danger maybe?' is the definition.
(eg nuclear disarmament might reduce danger)
'smart maiden worked out' is the wordplay.
'worked out' indicates anagramming the letters.
'smart'+'maiden'='smartmaiden'
'smartmaiden' anagrammed gives 'DISARMAMENT'.
(Other definitions for disarmament that I've seen before include "Finally decided on revising mainstream" , "Reduction in military forces and weapons" , "Removal of military weapons" , "possible subject of international agreement" , "subject for peace conference" .)