President Obama interrupted his vacation Wednesday to say the killing of U.S. journalist James Foley by ISIS "has shocked the conscience of the entire world" and declare that the Islamist extremist group will "ultimately fail" because its ideology is bankrupt.

"The one thing we can agree on is a group like ISIL has no place in the 21st century," Obama declared. Then he left to go play golf. Again.

Obama gets tough: That's the phrase you're likely to hear repeated over and over again on cable news and spread out across headlines online and in print. Like this:

But really it was all just part of a disturbing pattern of tough talk as a substitute for action. Step out of the New York-Washington bubble for a moment and you'll realize that the president's statement raised more questions than it answered:

What is Obama going to do about the Islamic State?

Wednesday's statement was the sixth on that subject since Aug. 7, when Obama announced that he had ordered U.S. warplanes to strike at Islamist extremist targets in Iraq, and we don't know any more about his plan to combat the ISIS now than we did two weeks ago.

Obama noted that "the United States of America will continue to do what we must do to protect our people. We will be vigilant and we will be relentless," but gave no specifics.

On Monday, the president made clear that his current approach of limited military operations was designed only to contain the group until a coalition of regional actors could be built to counter it — a hope he repeated on Wednesday.

Experts suggest that ISIS, also called the Islamic State or ISIL, poses an even greater threat to U.S. security than al Qaeda, because it's better-armed, better-funded and has control of territory that contains vital resources, such as oil — and waiting to confront it may be unwise.

"This may be a question of pay now or pay later, and paying later may actually be a much higher bill," former CIA Director Michael Hayden said on Fox News on Tuesday.

Grievances against the group go deeper than the murder of Foley, who went missing while reporting in Syria in 2012. Obama noted that Islamist extremists "have rampaged across cities and villages — killing innocent, unarmed civilians in cowardly acts of violence. They abduct women and children, and subject them to torture and rape and slavery. They have murdered Muslims — both Sunni and Shia — by the thousands.

"They target Christians and religious minorities, driving them from their homes, murdering them when they can for no other reason than they practice a different religion. They declared their ambition to commit genocide against an ancient people."

But Obama's greatest concern right now is avoiding "mission creep."

If the Islamic State is such a threat to Muslims, why aren't they fighting it?

Obama noted that the group "speaks for no religion" and "has no ideology of any value to human beings.

"From governments and peoples across the Middle East, there has to be a common effort to extract this cancer, so that it does not spread," he declared.

"There has to be a clear rejection of these kind of nihilistic ideologies. One thing we can all agree on is that a group like ISIL has no place in the 21st century," he said.

Unfortunately, that's not entirely true.

Though the Islamic State embraces a particularly extreme brand of Islam that views most other Muslims as heretics, and has been condemned by leading Islamic authorities in both Saudi Arabia and Egypt, there are both religious and political reasons why potential U.S. allies in a fight against the group either stay on the sidelines or even cooperate with the extremists.

The sectarian Shia-led government of former Iraqi Prime Minister Nouri al-Maliki, for example, drove many Sunni Arabs to welcome the Islamic State as a refreshing change, just as they had done with al Qaeda before an intensive U.S. campaign to wean them away from the extremists.

And many Arab Gulf governments, most notably Kuwait and Qatar, tolerate financial support by some of their citizens for Islamist extremists (and in some cases provide it themselves) both to placate sympathizers among their own populations and as a tool to gain influence in the Middle East.

Saudi Arabia, which has considerably hardened its stance toward extremism as it becomes clear that the Islamic State has the kingdom in its sights, hasn't yet seemed willing to commit forces to fight the group.

It's going to take a serious U.S.-led effort to build any kind of anti-Islamic State coalition in the near future. And Obama has shown no willingness to invest U.S. leadership in such an effort.

Meanwhile, many Westerners, including Americans, are arriving to join the group. Newsweek reported Wednesday, quoting a British parliamentarian, that "more than twice as many" British Muslims are fighting for the ISIS than are serving in the British armed forces.

So, who will do it if the U.S. won't?

Iran. The Shia theocracy in Tehran is a bitter enemy of the Sunni extremists of the Islamic State, who are just as likely to target Shia Muslims for extermination as they are Christians, Jews or Yazidis.

It's no secret that Iranian forces are helping the Iraqi government fight the Islamic State, after having backed Syrian dictator Bashar Assad all along, and European leaders, tired of waiting for the United States, are exploring the possibility of drawing Tehran into a coalition.

That may be what Obama is counting on. After all, he's worked hard to use the ongoing talks over Iran's nuclear program to open the door to rapprochement with Tehran — even to the point of keeping other issues off the table. Achieving a deal on Iran's nuclear ambitions is one of the top two priorities of his policy in the Middle East.

But deeper Iranian involvement may drive away other potential allies in the fight against the Islamic State — most notably Saudi Arabia — and there are many Sunnis in the region who fear Iran more than they fear the extremists.

OK, what can we do differently?

It's hard to believe that it's been almost 13 years since the Sept. 11 attacks and no U.S. president has yet made a clear statement of what principle should guide the conflict sparked by that act of terrorism: The world is not big enough for the U.S. and violent Islamist theocracy to coexist. One of them has gotta go, and it ain't us.

To paraphrase former Bill Clinton campaign strategist James Carville: "It's the ideology, stupid."