The files has also shown that the militant group has been training foreign fighters to attack Western targets for much longer than security services had suspected and the Sky news has told that their exclusive investigation into leaked secret IS files suggests one piece of co-operation was over the ancient city of Palmyra.
The revelations underscore fears in the United States that a network of sleeper cells is spread across Europe, avoiding detection, and is planning further Paris- and Brussels-style assaults and IS defectors have told Sky News that Palmyra was handed back to government forces by Islamic State as part of a series of cooperation agreements going back years.
For the past 18 months the Sky News has maintained contacts with a Free Syrian Army group originally from Islamic State's headquarters in Raqqa, but now living across the border in Turkey and the group operates a network to smuggle defectors away from IS.
The Islamic State wants to maintain and expand its caliphate across historical Muslim lands while attacking and provoking a war with the West, and dividing societies and it is a long term plan, the details of which we are only just learning.
