MAP: Here's A Rundown Of The Jihadist Offensive That's Shaking Iraq

An offensive by extremist militants under the banner the Islamic State of Iraq and ash-Sham has shaken Iraq to its core, capturing various cities in the country's north and exacerbating sectarian tensions.

Reuters published a graphic showing how quickly ISIS began carving up the country last week:

On Sunday, the U.S. began drawing drawing down staff at its embassy in Baghdad in response to a threat posed by violence for the first time since 2003. Between 50 and 100 U.S. Marines and U.S. Army personnel arrived at the embassy to bolster security.

On Monday, Iraqi forces reportedly targeted militants northwest of Fallujah in an airstrike. ISIS has been threatening to enter Baghdad but would have a difficult time capturing and holding the city of 8 million - especially now that Iranian forces are involved to protects Tehran's interests in the Shia-dominated south.