As violence continues to wrack Iraq, the United Nations warned Saturday of another ethnic slaughter in the making by Sunni extremists from ISIS.

ISIS fighters have besieged the ethnic Turkmen Shiite town of Amerli in the north for two months, and its 20,000 or so residents are without power and running out of food, water and medical supplies…

The people are surrounded and relying on the Iraqi government to take them out by helicopter or support them with food drops, Albayati said. In the last 10 days, he added, only one flight has delivered food.

Western powers are coming under mounting pressure to do more to confront Islamic State (Isis) in its stronghold in Syria, as the heavily armed militants edged closer to taking an important air base that would cement their domination over a swath of the country’s north…

“The Islamic State is now the most capable military power in the Middle East outside Israel,” a senior regional diplomat said on Friday.

US officials have conceded that 93 air strikes in Iraq that have checked the Isis advance in the past 10 days will not deal definitively with the jihadis, and that they will have to be confronted in Syria to be fully defeated.

On a strictly human level, that we are shocked by what we are seeing is understandable. But it is also symptomatic of a deeply problematic worldview. Here in the West, we have grown so accustomed to chanting “never again” that when extraordinary evil unabashedly presents itself for our acknowledgment, we are left somewhat nonplussed. This, in our conception, simply can’t be happening. The man who murdered James Foley employed a technique that would have been frowned upon by even the most bloodthirsty monarchs of the Tudor dynasty. Henry VIII — no paragon of marital virtue he — cut the heads off two of his wives and, outside of his connubial exploits, was not entirely averse to putting heads on spikes. But even in post-medieval England, executions were quick and relatively painless. Anne Boleyn was killed by a single blow, the king having hired a skilled swordsman from France to ensure the job was done professionally. Also elegantly dispatched were Edmund de la Pole and Edward Stafford, both of whom were plotting to kill Henry and take his throne; John Fisher, who refused to accept Henry’s position as the head of the Church; and Thomas Cromwell, who, having been a longtime favorite, was eventually deemed too Lutheran for Henry’s tastes. American journalist James Foley, by contrast, had his throat slowly cut with a tiny, possibly blunted knife, his head clumsily sawn off over seven agonizing minutes. Goats have been afforded better endings. Can this be real?

Many among us seem incapable of believing that it is.

Earlier in the three-year-old Syrian uprising, Mr. Assad decided to mostly avoid fighting the Islamic State to enable it to cannibalize the more secular rebel group supported by the West, the Free Syrian Army, said Izzat Shahbandar, an Assad ally and former Iraqi lawmaker who was Baghdad’s liaison to Damascus. The goal, he said, was to force the world to choose between the regime and extremists.

“When the Syrian army is not fighting the Islamic State, this makes the group stronger,” said Mr. Shahbandar, a close aide to former Iraqi Prime Minister Nouri al-Maliki, who said Mr. Assad described the strategy to him personally during a visit in May to Damascus. “And sometimes, the army gives them a safe path to allow the Islamic State to attack the FSA and seize their weapons.”

“It’s a strategy to eliminate the FSA and have the two main players face each other in Syria: Assad and the Islamic State,” said Mr. Shahbandar. “And now [Damascus] is asking the world to help, and the world can’t say no.”

Ransom payments for kidnap victims, crimes like extortion and robbery and, lately, oil sales are believed to have brought in “hundreds of millions of dollars” for ISIS during its two-year reign of terror, U.S. intelligence officials tell NBC News. But the group is burning through money nearly as quickly, fighting a two-front war in Syria and Iraq and trying to govern the self-declared “caliphate” it has established, they say.

The Islamic terror group’s annual revenues are now at least comparable to the funding that al Qaeda had available during its heyday in the late 1990s and early 2000s, when U.S. intelligence estimated it was bringing in $25 million to $30 million a year, according to one official. And it may be that ISIS’s financial resources go “well beyond” those of Osama bin Laden’s organization at the time, the official said…

He added there are logistics issues, moving men and materiel as well as feeding, clothing and tending to the medical needs of their fighters. Also, traditionally, the families of “martyrs” killed in action get pensions.

And ISIS has a new expense. “The cost of governance, paying administrators in the towns and cities they have captured and incorporated into their caliphate,” said the first official. “Running a caliphate is not cheap.”

American intelligence agencies are working on a thorough assessment of the group’s strength, and they believe that its ability to gain and hold territory could make it a long-term menace in the Middle East. Intelligence officials said there were indications that ISIS’ battlefield successes had attracted defectors from Qaeda affiliates in Yemen and Africa, who are eager to join a group with momentum…

Some experts said the fear of ISIS was driven partly by how little is known about the organization. While the United States has spent more than a decade studying Al Qaeda, officials know comparatively little about the structure and leadership of ISIS, beyond the information they have on the group’s self-appointed caliph, Abu Bakr al-Baghdadi…

“I’m worried about Turkey, I’m worried about Jordan, I’m worried about regional destabilization,” said Jarret Brachman, the author of “Global Jihadism: Theory and Practice” and an adviser to the United States government on ISIS and Al Qaeda.

The three British newspapers devoted page after page to exploring the scale of British terrorist recruitment, the danger that the terrorists will come home, and clear warnings from the security forces that they will be overwhelmed if they come home in an organized manner.

Something profound is happening when a vicious, radical movement can recruit that many young men from a society that was housing, feeding and educating them. This represents a repudiation of the idea of assimilation on a scale and intensity that will lead to profound public policy changes…

I urge you to read President Obama’s full text. It isn’t very long. The most delusional line is his assertion that “people like this ultimately fail. They fail because the future is won by those who build and not destroy.” Of course it is freedom and the rule of law that have been rare throughout history, and tyranny and lawlessness that have been common. ISIS and the ideology it represents won’t just wear themselves out.

One has to wonder whether the President understands how serious a threat ISIS presents. ISIS is a fact. It is a religiously motivated movement that uses terror as one of its weapons. Beheading people is nothing new in history.

One of my fears in the early years of the Iraq war was that if it proved to be the wrong war—if no weapons of mass destruction were found, if sustained unrest showed Saddam Hussein was the garbage-pail lid who kept the garbage of his nation from spilling out—it would mean that at some time in the future when America really needed to fight and had to fight, she would not. I feared the war’s supporters would be seen to have cried wolf, and someday there would be a wolf and no one would listen. Now there is a wolf.

We tell ourselves that we do not want to go back to Iraq, and we don’t—all the polls show this. But facing up to what ISIS is and what it plans to do is not returning to Iraq in that we are not talking about nation-building, quixotic exercises in democracy-bringing, or underwriting governments ruled by incompetents. We are talking about other things…

Continue bombing ISIS where potentially efficacious, as heavily and for as long as needed. This week’s bombing forced them to give up the dam they’d seized at Mosul, an act that left ISIS looking, for the first time in its history, reduced and stoppable. Go to Congress for authorization of force, showing the world we have gained at least some semblance of unity. Give the Kurds, our actual friends, every kind of help they need, from military to material. Use the threat of ISIS to forge new bonds with allies and possible allies, such as the leaders of nearby countries that are immediately threatened. Go to the U.N., pound the table, ask for the world’s help. Let them humiliate themselves by doing nothing if that’s what they choose. At least it will be clarifying.

And be prepared, to the degree possible, for a hit or hits on American soil or that of our long-standing allies. ISIS says it’s coming. So far they’ve done pretty much everything they said they’d do.

They are, in an Orc-like way, almost the perfect enemy: So extreme in their methods and coldly ascetic in their vision that even fellow Islamic extremist organizations and authoritarian regimes have turned against them in revulsion. While their military success has been impressive, they have united a surprisingly wide variety of nations, factions, faiths and forces against them.

We are now witnessing the spectacle of a Coalition of the Begrudgingly Willing that has brought together the United States, Hezbollah, Iran, Iraq, Europe, Canada, Turkey and the Kurdish People’s Party in an extremely awkward but very real alliance against the black flag.

So, as distasteful as this may sound during a week in which the group decapitated a journalist and pledged genocidal murder, it is worth asking whether the Islamic State is the best possible enemy that could have emerged from the chaos of the post-Iraq war, post-Arab Spring Middle East. Unlike other potential threats, this one has transformed the politics of the region in profound ways. While still posing a terrible threat to thousands of lives, by attempting to form a grotesque Caliphate, the IS fighters have provoked many changes that were long overdue.

For now, Obama can get away with stretching the existing rationale, but not if he is to conduct a sustained campaign. For this you must make the larger case that we simply cannot abide a growing jihadist state in the heart of the Middle East, fueled by oil, advanced weaponry and a deranged fanaticism.

These are the worst people on earth. They openly, proudly crucify enemies, enslave women and murder men en masse. These are not the usual bad guys out for land, plunder or power. These are primitive cultists who celebrate slaughter, glory in bloodlust and slit the throats of innocents as a kind of sacrament…

“People like this ultimately fail,” Obama said of Foley’s murderers. Perhaps. But “ultimately” can be a long way — and thousands of dead — away. The role of a great power, as Churchill and Roosevelt understood, is to bring that day closer.