New intelligence assessments show that the number of Islamic State fighters has dropped in Iraq and Syria but is rising in Libya, a senior U.S. defense official said Thursday. According to the official, reports suggest there are 19,000-25,000 IS fighters in Iraq and Syria, compared to an earlier range of 20,000 to more than 30,000. The newly declassified numbers back up recent comments from military commanders and other defense officials who have argued that the U.S.-led coalition airstrikes are having an impact on Islamic State militants and causing them to lose ground in both countries. ...