Liberté, égalité, fraternité, et la solidarité. My limited understanding of
ISIS was challenged by this article in the Atlantic:
http://www.theatlantic.com/magazine/archive/2015/03/what-isis-really-wants/384980/ . Graeme Wood has done some careful research and challenges some commonly held beliefs. After reading this I'm convinced that the West should:
1. Declare war on the caliphate and treat citizens who have dealings with it under the good old statutes of treason, etc..
2. As the caliphate depends on holding territory, give maximum aid to alternative claimants to the territories they have a legitimate claim to and can control.
3. Selectively destroy munitions, military infrastructure, administrative centers etc. as we would do with any conventional enemy.
4. Above all avoid any rash changes in foreign policy. I see no need to change our policies on Syria, for instance. Assad needs to go, the refugees need help.
N.B. Some further clarification of Wood's position can be gleaned from his discussion with Sam Harris:http://www.samharris.org/blog/item/the-true-believers .