There is no consensus on how to pronounce ISIS, either. Many people say ‘eye-sis,’ the way most English speakers (notably including Bob Dylan) would pronounce the name of the ancient Egyptian goddess Isis. When an English word begins with I, followed by a single consonant and another vowel, the long I sound is generally used. But ‘ee-sis’ is also frequently heard, perhaps because these days both Iran and Iraq are often pronounced beginning with a long E sound. So far, those using the Levant version seem to be speaking the abbreviation letter by letter — ‘eye, ess, eye, ell’ — more often than making an acronym out of it.