ISIS 'caliphate' near collapse as most of Raqqa taken by U.S.-backed forces The end for the Islamic State's self-proclaimed caliphate is near, three years after the terrorist group announced its vision for creating a nation state across Iraq, Syria and the wider region. U.S.-backed forces are on the verge of capturing the group's home base, Raqqa, Syria, the last major city it still holds. A U.S.-