(CNN) — A 10-nation group the Obama administration has gathered to fight ISIS could help, but more important will be the nations that surround the Islamist militant group’s self-declared “caliphate,” experts say.

After meetings at last week’s NATO Summit, U.S. Defense Secretary Chuck Hagel spoke of a newly formed “core coalition.” President Barack Obama said it would take on ISIS. The nations are Australia, Britain, Canada, Denmark, France, Germany, Italy, Poland and Turkey, in addition to the United States.

(Link)