A few days after the 9/11 attacks, George W. Bush began repeating what would become a mandatory presidential preamble.

"The face of terror is not the true faith of Islam," he declared, then quoted from the Qur'an to make that case: "In the long run, evil in the extreme will be the end of those who do evil.

"Islam," Bush concluded, "is peace."

For the rest of his time as president, Bush was careful to use similar language in his denunciations of al-Qaeda and the Taliban. And when Barack Obama took over, he used an identical set of talking points.

Last week, speaking to a gathering of some 60 countries about the need to counter and destroy ISIS, the jihadist group running amok in Iraq and Syria, Obama couched his message in the same Islam-is-peace language, fishing out another quote from Islam's sacred text: "The Qur'an says whoever kills an innocent, it is as if he has killed all mankind."

Obama, in fact, goes even further than Bush did. To the annoyance of his critics, this president conspicuously avoids in his descriptions of ISIS and al-Qaeda any adjectives pertaining to their declared religious motivation.

Obama will not speak the words "Islamic," and "extremist" in the same breath. He will not use "Islamist," or even "jihadist."

Why Obama and some other Western leaders frame their rhetoric that way is obvious.

They want to shield law-abiding Muslim citizens from popular anger as provocations grow more atrocious by the month. Plus, they are anxious to repudiate any idea of a war between the largely Christian West and the Islamic world.

But that is the way ISIS and its fellow travellers see things, and those atrocities — the immolation of the Jordanian pilot in the name of Allah, the internet videos of hooded figures hacking the heads off Western hostages in the name of Allah, the slaughter at a French magazine in the name of Allah — are having the desired effect.

It's pretty safe to say that in the broad public mind, both here and in Europe, Islam is not synonymous with peace.

Terri Crippes, left, and Lori Lyon, are the maternal aunts of Kayla Mueller, a 26-year-old American woman who had been held by Islamic State militants and was confirmed dead earlier this month. (The Associated Press)

And hovering above all the reassurances that the vast majority of Muslims reject religious extremism is the question of why so many violent religious extremists today are Muslims.

An answer, of sorts, is provided in a recent disquisition in The Atlantic, one of the oldest and most respected magazines in America.

The author, Graeme Wood, argues that whatever you might think of ISIS, it is following Qur'anic dictates.

The quotes extracted by George W. Bush and Obama do exist in the Qur'an, but so do plenty of others that are anything but peaceful.

A broader narrative

"Muslims can say that slavery is not legitimate now, and that crucifixion is wrong at this historical juncture," writes Wood. "Many say precisely this. But they cannot condemn slavery or crucifixion outright without contradicting the Qur'an and the example of the Prophet."

Wood argues that this limitation is what prevents many Muslims from speaking out against hardline Islamists.

The article is exhaustive, deeply researched, and quotes not just doctrinaire jihadists, but a widely respected Islamic scholar at Princeton University, as well as some of ISIS's supporters.

British Prime Minister David Cameron is one of those allies not avoiding the term 'Islamic extremism.' He deployed it again as recently as this week when talking about the three British school girls trying to make their way to Syria. (The Associated Press)

And it's provoking a public discussion here — on both the U.S. left and right — that a good many Americans have clearly been itching to have.

Reading the text of President Obama's speeches these past weeks, one suspects he read The Atlantic article, too, and that he's anxious to retain control over any such discussion.

Al-Qaeda and ISIS "draw selectively from the Islamic texts," Obama argues.

Having said that, though, he does concede there is "a broader narrative that does exist in many Muslim communities around the world that suggests the West is at odds with Islam in some fashion. Or that we are the cause of every ill in the Middle East."

That's not the case, the president said, adding that Muslim leaders, including scholars and clerics, need to do more to push back.

Basically, he was saying, if you aren't part of the solution, well … the conclusion is obvious.

Denunciations

Mainstream Western Muslim groups, one suspects, probably think they've already been as clear as they need to be about violence in the name of their God. And the conclusions in The Atlantic article are even less welcome.

Jerusha Tanner Lamptey, a professor of Islam and ministry at Union Theological Seminary in New York, was quoted by the group ThinkProgress as saying Wood's article in The Atlantic effectively portrayed all Muslims as archaic, backward-minded literalists, unable to accommodate the modern world.

Of course, if the most sacred texts of Islam contain some pretty unpeaceful passages, so does the Bible. The book of Leviticus, for example, outright condones slavery. The Old Testament preaches against homosexuality, and some of the punishments it prescribes for sinners are as savage as ones dispensed by ISIS.

Obama himself has pointed out recently that Christians have committed deeply evil acts in the name of Jesus, citing in particular the Crusades and the horrors of the Inquisition. (For this he took heavy criticism from Christian leaders, who cried false equivalence.)

The point he seems to be making is that no religion "is peace," in and of itself. Most religions in fact have adherents capable of fundamentalist, violent interpretations. At this point in history, Islam seems to have the most ferocious ones.

In any event, pretending that the likes of ISIS and al-Qaeda and al-Shabaab have nothing whatever to do with Islam is unpersuasive. Would anyone argue that the Crusaders, who butchered Jews and Muslims with equal enthusiasm, had nothing whatever to do with Christianity?

Obama must know that his carefully laundered messaging is increasingly met with mockery. Even some Democrats are rolling their eyes.

Here in the U.S., a conversation is certainly under way about whether Islam, at least as practised in its birthplace, is as intrinsically peaceful as the two most recent American presidents have claimed.

It's going to be difficult to have this conversation without offending a lot of people, or exciting those nativists who have nurtured resentment and even hatred of Muslims since 9/11.

But it's taking place. The question is whether it can proceed sensibly.