Climate warmed with this shelter plunged into river? (7)
I believe the answer is:
detente
'climate warmed with this' is the definition.
The definition suggests a singular noun which matches the answer.
'shelter plunged into river?' is the wordplay.
'shelter' becomes 'tent' (tent is a kind of shelter).
'plunged into' indicates putting letters inside.
'river?' becomes 'dee' (River Dee).
'tent' put inside 'dee' is 'DETENTE'.
Can you help me to learn more?
(Other definitions for detente that I've seen before include "Easing of hostility between nations" , "Easing of international tension" , "Slackening of tension" , "Relaxed relations" , "Easing of hostilities" .)