“The lack of progress has hardened feelings of embitterment and emboldened hard-line rejectionists on both sides of the divide.”

“Street brawls arising out of the embitterment of feeling were not infrequent.”

“But if America came to be seen as an ally of the Shia, it would do little to assuage the Sunni embitterment that feeds IS's appeal.”

“This is not good for anybody, except for a few curmudgeons and people who are embittered by nothing more than their own embitteredness.”