A real killer elite

For more than 30 years, a top secret US special operations intelligence unit known only as "the Activity," or more recently Task Force Orange, has operated in the shadows, tracking down America's enemies around the world for Delta or SEAL Team Six to kill or capture, or more recently for Reaper drones to assassinate from afar. In an excerpt from the brand new eBook of his history of the Activity, "Killer Elite," Michael Smith describes its role in the fight against Islamic State in Syria, Libya and Iraq.

The killing of Abu Musab al-Zarqawi in 2006 had caused extensive damage to al-Qa'eda in Iraq. It changed its name to Islamic State in Iraq but the surge in US troops and the successful recruitment of Sunni sheikhs to help counter the insurgency resulted in the Activity, Delta and their British SAS allies hunting down and killing most of the group's leadership. When Abu Bakr al-Baghdadi took over in 2010, he moved it to Syria to regroup and, after the civil war broke out in 2011, absorbed all of the Syrian al-Qa'eda affiliates, claiming to have the backing of new al-Qa'eda leader Ayman al-Zawahiri.

It was a lie, but with al-Zawahiri in hiding even the leaders of al-Nusra Front, the main al-Qa'eda group, believed it. Buoyed by its new recruits, ISIS gained substantial ground across northern Syria. But when al-Zawahiri discovered the deception behind the new Islamist alliance, he broke off all ties with ISIS. The response from al-Baghdadi was to declare himself the "Caliph" of a worldwide Islamic Caliphate and rename his group Islamic State, reflecting his new more global ambitions of replacing al-Qa'eda as the principle threat to the West.

By now his success in gaining ground and the simple but brutal pseudo-Islam terror imposed on any opponents, with the men murdered and the women forced into sexual slavery, had gained the group a substantial number of ruthless and battle-hardened followers. They swept into Iraq and, by June 2014, they controlled Mosul, Iraq's second city, and more ominously the town of Fallujah just 40 miles west of the capital Baghdad.

President Obama sent US Army special forces in to help the Iraqi military but was adamant he would not put troops on the ground in Syria. Yet even as Obama spoke, the Activity was already back in its old hunting ground preparing the way for what was ultimately a failed attempt by Delta to rescue two U.S. journalists who were being held by Islamic State at its "capital" in Raqqa.