...is about to ally with Sweden (7)
I believe the answer is:
resides
'is' is the definition.
The answer and definition can be both to do with fundamental existence as well as being verbs in their -s form.
Perhaps there's an association between them I don't understand?
'about to ally with sweden' is the wordplay.
'about' becomes 're' ('re' means regarding or about).
'to ally with' becomes 'side' (I've seen this in another clue).
'sweden' becomes 's'.
're'+'side'+'s'='RESIDES'
Can you help me to learn more?
(Other definitions for resides that I've seen before include "stayed in Scotland" , "Sojourns" , "stays in Peebles" , "Lives, dwells" , "stays required" .)