Rapprochement - noun
the development of friendlier relations between countries or groups of people who have been enemies
Definition:
1: establishment of or state of having cordial relations
Source:
http://www.merriam-webster.com/dictionary/rapprochement
Encounter:
I was reading an article on the New York Times about Obama opening relations with Cuba, and I had no idea what this term meant so I looked it up. Rapprochement means to develop friendlier relations with Cuba in this case.