The way to defeat the East (5)
I believe the answer is:
route
'the way' is the definition.
(route is a kind of way)
'defeat the east' is the wordplay.
'defeat' becomes 'rout' (routing is a kind of defeating).
'the east' becomes 'e' ('E' can be a synonym of 'east').
'rout'+'e'='ROUTE'
'to' is the link.
(Other definitions for route that I've seen before include "Course taken" , "Way, path" , "Course of 7" , "Course, road" , "Path to follow" .)