This is coolbert:
Reading this headline my instantaneous reaction was tunnel warfare. Going underground literally. But that is not so. Underground as meaning more surreptitious and clandestine. More hidden.
"ISIS reportedly goes underground as activists dispute airstrikes' effectiveness"
"Members of the Islamic State militant group have begun traveling by night and in small groups in an effort to avoid detection by U.S. and Arab forces carrying out airstrikes in Syria and Iraq, according to a published report."
"the group, commonly known as ISIS, has also relocated weapons and hostages and moved out of bases, buildings, and camps they had occupied prior to the strikes."
. . . .
". . . U.S. officials tell the Journal that early efforts at camouflage by ISIS have been largely unsuccessful, though the militants are expected to grew more adept at covering their tracks."
Dispersal and redundancy. Constant movement. Camouflage and concealment. AND deception.
ISIL brutal and ruthless as well. Expect them to use hostages as human shields and make it plain to the world that hostages are being used in this manner.
And ISIL combat units when in contact with adversaries also to use "hugging" tactics. Close the gap between you and the enemy to thirty meters or less and not allow for close-air-support [CAS] to be used against you.
Hardly also expect ISIL will eventually revert to tunnel warfare. And employing what is best described as impressed or slave labor to dig the tunnels.
These ISIL guys are not stupid or dumb.