embold embolden forces to retake mosul. iraq's second largest city, captured by isis in june of 2014. u.s. officials say preparations have already begun as u.s.-backed iraqi security forces and kurdish pashmerga capture crucial territory around mosul, a city of some 2 million people. >> you have to think of it as a rolling kind of campaign to isolate and squeeze, learn more about the information that's happening there. >> mosul is very complicated. there's sa, sunni, arab, kurd. we want to make sure everything is synchronizeds and working together. >> the sectarian tensions further enflamed around the region as several sunni gulf states led by saudi arabia cut dib mattic ties with shiite iran. tensions stoked when saudi arabia executed a prominent shiite cleric, leading iranian