I just posted this video by the Institute for the Study of War "ISIS vs the Iraqi Security Forces: Can the State of Iraq Survive?" Very informative about IS's capabilities and campaign. IS has fighters in reserve to the west and south of Baghdad that are not involved in current offensive. It has also been able to carry out simultaneous offensive operations in both Syria and Iraq showing its manpower strength. IS's campaign against Baghdad is coming but hasn't started yet are some of the highlights of the video.