Isis faces exodus of foreign fighters as its 'caliphate' crumbles

Exclusive: Two Britons and one US citizen are among dozens who have surrendered or been caught at Turkish borderLarge numbers of foreign fighters are abandoning Islamic State and trying to enter Turkey, with at least two British nationals and a US citizen joining an exodus that is depleting the ranks of the terror group.Stefan Aristidou, from Enfield in north London, his British wife and Kary Paul Kleman, a resident of Florida, last week surrendered to Turkish border police after more than two y