Unfortunately, it is the brutality of ISIS which seems to have attracted these foreign fighters.
That and money. ISIS are savages, so they will always attract sociopaths. There aren't many places or societies in the world, that will not only allow you to kill a bound hostage, but also praise you for it and even pay you.These middle-eastern groups seem to have an endless supply of oil money.
because they have their own oil fields in iraq and syria - they sell the usually unrefined oil to assad, turkey and some states of the EU.
And well, from there it probaly can go pretty much everywhere...
tbh the chances are high that assad is more or less actively supporting isis as leverage against the west.
and turkey with there pretty much neutral stance doesnt help much either as one of the biggest players in that area.
also this is only a part of their finance; they get money from human trafficking, exortion, kidnapping, donation.
in big areas they are already acting as government, providing people with water/electricity, taking taxes; actual numbers say they control an area with more then 2 million inhabitants.
the situation is super bad and i dont see a solution without the use of ground force.
