My bases, perhaps, in ambassador's residence (7)
I believe the answer is:
embassy
'ambassador's residence' is the definition.
(I've seen this before)
'my bases perhaps' is the wordplay.
'perhaps' indicates an anagram.
'my'+'bases'='mybases'
'mybases' is an anagram of 'EMBASSY'.
'in' is the link.
(Other definitions for embassy that I've seen before include "Residence of an ambassador" , "Consulate" , "Diplomatic outpost" , "foreign mission abroad" , "Legation" .)