The Iraqi province of Diyala lies to the north of Baghdad. Its shares its eastern border with Iran, its northern border with Kurdistan, and its western border is shaped by the flow of the Tigris River. The Diyala River, a tributary of the Tigris, flows south through Diyala before meeting with the Tigris just south of Baghdad. Diyala's main cities include Baqubah (its capital), Muqdadiyah, Balad Ruz, Khalis, and Khanaqin.  The province has a mix of Sunni Arab, Shi'a, and Kurdish residents.

Al Qaeda in Iraq (AQI) was the most destabilizing threat to Diyala in 2006.  The province had special significance for al Qaeda.  Abu Musab Zarqawi designated Diyala the capital of the caliphate that he aimed to establish in Iraq when he was head of al Qaeda in the country.   In April 2006, Zarqawi located his headquarters at Hebheb, a village northwest of Baqubah along the Baghdad-Kirkuk road.

Al Qaeda terrorists lived in rural areas, but concentrated in safe houses inside Baqubah.  They discredited the Iraqi security forces through numerous attacks, and they discredited the Iraqi government by threatening employees with death if they showed up for work.  The organization used the canalized terrain east and southeast of that city, the former hunting grounds of Saddam Hussein stretching from Balad Ruz to Turki Village, as a major supply base for its Diyala and Baghdad operations.  A violent, Wahhabist organization called the Council imposed its version of Shari’a law on those villages.  The Council killed Shia males and displaced Shia families.

 Al Qaeda also based itself in villages in the Diyala River Valley, northeast of Baqubah.  They fought to control Muqdadiyah, which established a line of communication to Lake Hamrin.  From there, al Qaeda maintained communications along roads into Iran via Khanaqin and into the Kurdish provinces via Kirkuk.  Finally, al Qaeda established itself in the Khan Bani Sa’ad tribal area south of Baqubah, all the way down to Salman Pak, south and east of Baghdad.  These areas were under al Qaeda control – whether through physical presence or psychological intimidation – by November 2006.

In addition to al Qaeda, extremist Shia militias, sectarian leaders in the province's security forces, and Iranian funded Special Groups aggrevated sectarian differences and challenged Coalition forces throughout 2007.  Diyala acted as a conduit for Iranian weapons and advisors moving into Iraq, both into and from Baghdad.

Security for Diyala province is the responsibility of Multinational-Division North (MND-N) and the 5th Iraqi Army Division. Operations Arrowhead Ripper, Lightning Hammer I and Lighting Hammer II, and Iron Hammer all aimed to clear extremist elements from Diyala.