ISIS is not just the terror group de jour. They are a hugely successful movement with an apocalyptic, nihilistic philosophy. When they say “convert, join us, or die”, they not only mean it, but they follow through with horrific effect.

But let’s look deeper. What else makes them such a real security threat, to Iraq, to the region, to the world, and to the U.S.? Here are 11 reasons.

1. ISIS is more media sophisticated than al-Qaeda and excels in using social media as a tool of terrorism. The group’s twitter and YouTube postings in English show that the West is often their target audience.

2. ISIS is flush with cash. ISIS’ territorial control allows for consistent stream of funding, and they‘ve developed an extensive extortion racket, as well as selling electricity and exporting oil and gas.

3. Because of ISIS rise to prominence, many al-Qaeda-linked groups are now pledging allegiance to al-Baghdadi’s ISIS, including elements of al-Qaeda in the Islamic Maghreb (AQIM), Ansar al-Dine (Tunisia) Boko Haram, and al-Qaeda in the Arabian Peninsula (AQAP), giving ISIS access to a global network of terrorists.

4. ISIS controls territory the size of Maryland in the heart of the arab world, which is important for a predominantly Arab revolutionary terrorist group. The al-Qaeda core group along the Afghanistan/Pakistan border controls no territory and is dependent on Afghan and Pakistani Islamist militants who act as hosts.

5. ISIS has evolved into a proto-state, with its own army, civil administration, judiciary and a sophisticated propaganda operation. Al-Qaeda core leaders are fugitives who are forced to live a clandestine existence under the constant threat of drone strikes or commando assaults.

6. ISIS is the most heavily-armed Islamist extremist group in history, having captured huge amounts of military weapons and equipment in Iraq and Syria.

7. ISIS is out-recruiting Al-Qaeda. It is estimated that 80 percent of the foreign militants that flock to Syria join ISIS, rather than al-Qaeda’s franchise, the Al-Nusra Front. ISIS appears to have success with recruitment of Westerners as well.

8. The leader of ISIS, who goes by the nom de guerre of Abu-Bakr al-Baghdadi, is a charismatic leader who claims descent from the Prophet Mohammed. This will help recruit young, impressionable Muslims. He has much more personal appeal for young Muslim militants than Al-Qaeda leader Ayman al-Zawahiri, a dour and didactic theoretician.

9. ISIS is better placed to not only attract recruits from the Middle East, North Africa, Europe and the United States, but get them into the fight. It is much easier to travel across the dissolving borders of Iraq and Syria than it is to travel to Pakistan or Afghanistan.

10. ISIS has declared the rebirth of the Caliphate and the leader of ISIS has proclaimed himself to be Caliph Ibrahim.

11. ISIS is the richest terrorist group in history. It looted at least five banks in Iraq, including Mosul’s central bank, which yielded more than $400 million dollars in gold and Iraqi currency. It controls oil fields in Syria and Iraq that generate income and it has pocketed millions of dollars in ransoms for hostages.

In summary, ISIS is an army, not just a terror group. ISIS is the biggest terror group ever. ISIS is actually established as a state, a caliphate at that, and it’s richer than al-Qaeda. It holds more territory than al-Qaeda, it’s drawing more recruits than al-Qaeda, and it’s more brutal than al-Qaeda.

This group must be forcefully addressed and stopped.