Follows and makes certain, with no resistance (6)
I believe the answer is:
ensues
'follows' is the definition.
(I've seen this before)
'makes certain with no resistance' is the wordplay.
'makes certain' becomes 'ensures' ('ensure' can be a synonym of 'make certain').
'with no' suggests deleting specific letters.
'resistance' becomes 'r' (abbreviation).
'ensures' with 'r' taken out is 'ENSUES'.
'and' is the link.
(Other definitions for ensues that I've seen before include "Follows as a consequence" , "Comes about, happens" , "Comes about as consequence" .)