You remember 2009 and the glow from Oslo— Barack Obama, Nobel Peace Prize winner. Wow. Less than a year into his presidency, hejoined an elite group: Nelson Mandela, LechWalesa, Martin Luther King Jr., Mother Teresa,the Dalai Lama. And for what? As near asanybody could tell, it was the only Nobel evergiven for future good intentions.

Now the president with the world’s mostprestigious badge of nonviolence is forced tobecome the warrior again, killing religiousextremists as he bombs his seventh Muslimcountry — one more, as Stephen Colbert notedwith a rewards punch card, and he’s earned afree falafel.

But look ahead, with optimism, and you cansee a design for long-term peace behind thepresident’s plan to simultaneously kill fanaticsand force a religion to confront the sources ofthat fanaticism. With his blunt speech at theUnited Nations on Wednesday, Obama puton notice the Sunni Muslim nations that haveallowed Sunni barbarians to spread.

He made it clear that it is a warped religiousideology — “the cancer of violent extremism”— that is behind the slaughtering of innocents,raping of young girls, beheading of aid workersand tourists. Yes, it was a lecture, with finger pointing. It’s time for the duplicitous Saudis,the look-the-other-way Qataris, “those who accumulate wealth through the global economy and then siphon funds to those who teach children to tear it down,” to stop trying to have it both ways. He called out their “hypocrisy,”without naming names, because everyoneknows who they are.

Sure, it’s just a speech. Words, following andpreceding airstrikes. But as a speech, it was astunning departure from the usual platitudeswithout a plan. The leader who didn’t have astrategy for dealing with Islamic State nihilistsa few weeks ago just dropped an idea bomb onthe rest of the world. The “Muslim” president— a falsehood still held by nearly 25 percent ofRepublican voters — gave the Muslim world ablueprint for saving itself.

Until this week, most Western leaders havebeen afraid to say what Obama said at the UnitedNations. Sunnis dominate Islam, a religion of1.6 billion people. The worst terror in the worldtoday is being waged on behalf of a small,violent cult of death that is nominally Sunni. Byenlisting at least five Sunni-majority nationsin his campaign against the Islamic State, alsoknown as ISIS or ISIL, Obama has taken the firststep to get Islam to do what it must do. (It would help to have Turkey, the only Muslim nation in the North Atlantic Treaty Organization, and a Shiite-majority country, fully aboard with the 50 countries in the campaign to quash ISIS.)

“No god condones this terror,” Obama said. “No grievance justifies these actions. There canbe no reasoning — no negotiation — with thisbrand of evil.” There again, his language wasunvarnished, without filter or diplomatic dither.

Many in Obama’s own party heard onlythe echoes of George W. Bush. “Evil-doers,”coming from Bush, was a punch line. Cue upWill Ferrell and Jon Stewart. O.K., parallelsgranted. But Bush’s war in Iraq was nationtopplingborn of hubris, followed by nationbuildingborn of ignorance. Obama’s directaction against ISIS is designed to keepentire communities of “infidels” from beingslaughtered by a cult under a black flag. Hisactions will save Muslims, the primaryvictims of Middle East terrorism, from otherMuslims. It’s also in America’s interest, for thoseisolationists who think we should never try tostop overseas massacres on our watch.

Obama, the peace prize winner, is the onlyperson who could rally the civilized worldagainst a caliphate of violence. Who else woulddo it? The pathetic, hapless and corrupt IraqiArmy, built with American tax dollars? TheUnited Nations? The Kurds? They will fight, butonly for their interests and their territory.

The military campaign, as always, is the easypart, and fraught with careful-what-you-wishforperil. War crimes trials, the sooner the better,for President Bashar al-Assad of Syria and anyname that can be clearly linked to a face behindthe mask of an ISIS executioner should proceedwith the support of the coalition Obama has puttogether.

But to earn his Nobel, Obama has to followthrough till the end of his presidency, to pressurethe Sunnis to police their own. This is theircancer, now spreading to the rest of the world.

No need to make it bigger than it is. The absurdlyalarmist voices in our country — LindseyGraham, with his fear that we’re going to “allget killed back here at home,” and the senatecandidate Scott Brown, who said “radicalIslamic terrorists are threatening to cause thecollapse of our country” — are myopics, staringout at the world from holes in the blankets overtheir heads.

More succinctly, as Obama stated, this fight is about what happens when religion goes bad. “There should be no tolerance of so-called clerics who call upon people to harm innocents because they’re Jewish, or because they’re Christian, or because they’re Muslim,” he said. “It’s time for a new compact among the civilized peoples of this world to eradicate war at its most fundamental source, and that is the corruption of young minds by violent ideology.”

Of course it’s a long shot. Of course it’s apipe dream. Of course it goes against all thebackward trends in the Islamic world. But in one of the best speeches of his presidency, Obama has shown the world a path to a peace that may outlast him.