between

米国は外交関係が断絶状態にあるキューバとの国交再開を目指す協議を開始すると発表しました。協議が成功裡に進むと歴史的に大きな出来事となります。

国際関係の話題ですが、どうしても語法で気になる箇所があります。Greenさん、このbetweenはどのような用法なのでしょうか。（UG）

U.S. to Restore Full Diplomatic Relations With Cuba, Officials Say

The United States will restore full diplomatic relations with Cuba and open an embassy in Havana for the first time in more than a half century after the release of an American contractor held in prison for five years, American officials said Wednesday.

In a deal negotiated during 18 months of secret talks hosted largely by Canada and encouraged by Pope Francis, who hosted a final culminating meeting at the Vatican, President Obama and President Raul Castro of Cuba agreed in a telephone call to put aside decades of hostility to find a new relationship between the island nation just 90 minutes off the American coast.

http://www.nytimes.com/2014/12/18/world/americas/us-cuba-relations.html?emc=edit_na_20141217