First, we need to get this one fact straight: all Muslims are not members of ISIS. There are two main divisions of Muslims, Shia and Sunni. Of the total Muslim population in the world of a bit above 1.5 billion, around 10-13% are Shia Muslims and other 87-90% are Sunni Muslims.

ISIS is a subset of Sunni Muslims, but by no means are all Sunni Muslims members of ISIS or affirmative of ISIS. A sign of this is that ISIS kills both Shia and Sunni Muslims, including Sunni clerics. Indeed, one of the braver Sunni clerics has condemned ISIS leader Abu Bakr al-Baghdadi to hell for distorting Islam.

They key belief that defines ISIS is that Islam is destined to rule the world, and essential to that goal is the extermination not only of infidels, especially Christians and Jews, but all Muslims who do not meet ISIS standards for Islamic purity.

In accordance with a fundamental tenet of Islam, infidels are given three choices: either convert, pay money to stay alive, or die. In the words of ISIS, “We offer them three choices: Islam; the dhimma contract—involving payment of jizya; if they refuse this they will have nothing but the sword.” These particular words were aimed at Christians in Iraq.

Paying the money, dhimma, does not mean that Christians or anyone else will be left alone. The payment is a sign that the non-believer submits to the laws of the state as defined by Sharia. As the Koran states, “Fight those who do not believe in Allah, nor in the Last Day, nor do they prohibit what Allah and His Messenger have prohibited, nor follow the religion of truth, out of those who have been given the Book, until they pay the tax in acknowledgment of superiority and they are in a state of subjection.” But even the paying of tax is a kind of lull in the overall fight to establish Islam as the religion. The Koran continues, “Say to those who disbelieve, if they desist [in their unbelief in Allah], that which is past shall be forgiven to them,” but “fight with them until there is no more persecution [of Islam] and religion should be only for Allah.” Persecution will cease, the reasoning of ISIS goes, only when Islam is established as the only faith.

Yet we must not forget that the sword is also used against the impure within Islam. That’s why ISIS kills Shia Muslims, the “wrong” branch of Islam.  And again, this demand for purity is aimed at all Muslims, Sunni or Shia, and reaches into the smallest aspects of life under ISIS rule. So, for example, we have the report from Iraq, that ISIS publicly executed 13 teenagers for watching an Asian cup soccer match. If one may trust the various Muslim sites on the internet where such things are discussed, playing or watching soccer is condemnable because it leads to Muslims praising non-believers, and hence eliminating the proper hatred of all Muslims toward non-believers, and, moreover, diverting their attention from thinking about jihad.

The horrors of ISIS have become routine.

ISIS routinely uses the internet as a terror tactic, relishing public beheadings as a source for spreading its own propaganda and fear as well—the latest being the beheading of 21 Coptic Christians.

ISIS routinely uses captured or kidnapped non-Muslim woman as sex slaves for its revolutionaries.

ISIS routinely kidnaps young males or entices impoverished boys with money, and makes them into loyal fighters for its goal of creating a caliphate to rule the world. “They captured my village and gave me a choice, “one 15 year old boy said.  “Either join ISIS, or be beheaded.” He noted that ISIS members gave out the anti-anxiety drug Zolam to those who were being strapped with suicide bombs, so they would go “out of their heads” and kill innocents by blowing themselves up. ISIS actually has a vast, tightly ordered recruitment network set up to lure in children as young as eight years old through an education system defined by ISIS’s goals.

The question is, of course, what is it about the particular kind of Islam that ISIS promotes that makes it routinely commit such evil acts?

We find part of an answer in the Boko Haram, the radical Sunni Muslim sect perpetrating every sort of atrocity in Nigeria. Boko Haram means something like “Western Education is forbidden.” That is, anything Western, i.e., non-Muslim, must be eliminated, and the chief source of contamination is education. But the official Arabic name for Boko Haram is Jama’atu Ahlis Sunna Lidda’awati wal-Jihad, which could be translated “People Committed to the Propagation of the Prophet’s Teachings and Jihad.”

In other words, like ISIS, the aim of Boko Haram is Islamic jihad, and that means elimination of the infidel, purification of Islam, and the establishment of a caliphate. While we in the West were all (rightly) outraged at the 12 gunned down in Paris by Muslims, we virtually ignored the Boko Haram’s slaughter of 2000people in a single attack in Nigeria at nearly the same time.

As with ISIS, Boko Haram knows the power of the internet as an instrument of spreading terror. To accompany a video showing them shooting civilians lying face down in a dormitory, we have the comments of one of their leaders: “We have made sure the floor of this hall is turned red with blood, and this is how it is going to be in all future attacks and arrests of infidels. From now, killing, slaughtering, destructions and bombing will be our religious duty anywhere we invade.”

The same is true for other similar jihadist groups dotting the northern half of Africa, Pakistan and Afghanistan, and even Indonesia and the Philippines. The Islamic goal of jihad justifies any kind of violence on its behalf. Beheadings, torture, using children for human shields, using woman and children as human bombs to blow up civilians—anything.

And so we have part of our answer. ISIS is not the only problem.  It is one manifestation of a problem within Islam. What seems to be a common factor in all such radicalized sects is a burning conviction that there can be no evil for those advancing jihad and imposing Sharia Law in its strictest sense. For them, that means that anything goes against non-believers, and even believers.

Just ask the Yazidi women who were kept as sex slaves of ISIS—the Yazidi are a non-Muslim minority being exterminated by ISIS in Iraq. You cannot ask the Yazidi who ended up in a mass grave. Nor can you ask the decapitated heads of Shia Iraqi soldiers and policeman that lined ISIS’s path of destruction in the fight for Bagdad in Iraq last June. You might be able to speak with some of the childrenbeing trained by ISIS as suicide bombers, or some of the children who are forced to the front lines to provide a human shield to ISIS fighters, and perhaps some of the children taken to the front as living blood banks for wounded soldiers. You cannot speak to the seven year old girl suicide bomber in Nigeria who a few days ago killed herself and seven others—a girl trained by the Boko Haram.

Anything that leads to victory is good. Anything.

Why? Why anything?

The answer does not come directly from the Koran or even the Hadith (the prophetic traditions about Mohammed), but from later Islamic jurists in the 9th century who divided the world into two: the House of Islam (Dar al-Islam), and the House of War (Dar al-Harb). These jurists were defining things in the context of Islam’s long-term expansion into (largely) Christian territories.

The picture is already obvious to the reader: there are Muslim dominated places in the world, and there are places where jihad has yet to conquer. According to this view, while there are limits to Islamic offensive war, whenever Muslims are attacked—and today’s jihadists always claim that Islam is under attack by the West—they may do anything and everything in response. Since all of the enemy (including civilians) are considered aggressors, then there is no limit to the killing. Since all Muslims are called to repel the aggression, not only men, but women and children must take up arms. Killing children and using children to kill, or killing women and using women to kill, or using civilians, women, and children as shields, or strapping bombs on them—all are licit.

That is how ISIS, and the growing number of like-minded Islamic groups, see the world. That is how they are training children as young as five to see the world. To understand, deeply, what this means, consider the following video where young Muslim children in Egypt post a video of a mock beheading of captives in gleeful imitation of the ISIS video showing the beheading of 21 Coptic Christians.

But again, we must understand that ISIS et al is not Islam. There are many within Islam who reject the anything goes view of war, which leads to the limitless horrors of Islamic terrorism. We in the West should be doing everything we can to connect to them as allies. And the more that ISIS and groups like it target these Muslims as victims, the more allies we should have.