article_snippet.sent: Just two years ago, they hadn't talked with each other officially in nearly four decades.
article_snippet.sent: It was tough, very intense at times, sometimes emotional and confrontational.
article_snippet.sent: It was a very intensive process, because the stakes are very high, and because there is a long history of not talking to each other.
article_snippet.sent: But the devil was in the details, and the numbers, timing, sequencing and verification procedures proved devilishly difficult to resolve.
highlights_snippet.sent: Talks were tough, intense and "sometimes emotional and confrontational," Kerry says .