LONDON — An existential struggle is taking place in the Arab world today. But is it ours or is it theirs? Before we step up military action in Iraq and Syria, that’s the question that needs answering.

What concerns me most about President Obama’s decision to re-engage in Iraq is that it feels as if it’s being done in response to some deliberately exaggerated fears — fear engendered by YouTube videos of the beheadings of two U.S. journalists — and fear that ISIS, a.k.a., the Islamic State, is coming to a mall near you. How did we start getting so afraid again so fast? Didn’t we build a Department of Homeland Security?

I am not dismissing ISIS. Obama is right that ISIS needs to be degraded and destroyed. But when you act out of fear, you don’t think strategically and you glide over essential questions, like why is it that Shiite Iran, which helped trigger this whole Sunni rebellion in Iraq, is scoffing at even coordinating with us, and Turkey and some Arab states are setting limits on their involvement?

When I read that, I think that Nader Mousavizadeh, who co-leads the global consulting firm Macro Advisory Partners, is correct when he says: “When it comes to intervening in the Arab world’s existential struggle, we have to stop and ask ourselves why we have such a challenge getting them to help us save them.”

So before we get in any deeper, let’s ask some radical questions, starting with: What if we did nothing? George Friedman (no relation), the chairman of Stratfor, raised this idea in his recent essay on Stratfor.com, “The Virtue of Subtlety.” He notes that the ISIS uprising was the inevitable Sunni backlash to being brutally stripped of power and resources by the pro-Iranian Shiite governments and militias in Baghdad and Syria. But then he asks:

Is ISIS “really a problem for the United States? The American interest is not stability but the existence of a dynamic balance of power in which all players are effectively paralyzed so that no one who would threaten the United States emerges. ... But the principle of balance of power does not mean that balance must be maintained directly. Turkey, Iran and Saudi Arabia have far more at stake in this than the United States. So long as they believe that the United States will attempt to control the situation, it is perfectly rational for them to back off and watch, or act in the margins, or even hinder the Americans. The United States must turn this from a balance of power between Syria and Iraq to a balance of power among this trio of regional powers. They have far more at stake and, absent the United States, they have no choice but to involve themselves. They cannot stand by and watch a chaos that could spread to them.”

Therefore, he concludes, the best U.S. strategy rests in us “doing as little as possible and forcing regional powers into the fray, then in maintaining the balance of power in this coalition.” I am not sure, but it’s worth debating.

Here’s another question: What’s this war really about?

“This is a war over the soul of Islam — that is what differentiates this moment from all others,” argues Ahmad Khalidi, a Palestinian scholar associated with St. Antony’s College, Oxford. Here is why: For decades, Saudi Arabia has been the top funder of the mosques and schools throughout the Muslim world that promote the most puritanical version of Islam, known as Salafism, which is hostile to modernity, women and religious pluralism, or even Islamicpluralism.

Saudi financing for these groups is a byproduct of the ruling bargain there between the al-Saud family and its Salafist religious establishment, known as the Wahhabis. The al-Sauds get to rule and live how they like behind walls, and the Wahhabis get to propagate Salafist Islam both inside Saudi Arabia and across the Muslim world, using Saudi oil wealth. Saudi Arabia is, in effect, helping to fund both the war against ISIS and the Islamist ideology that creates ISIS members (some 1,000 Saudis are believed to be fighting with jihadist groups in Syria), through Salafist mosques in Europe, Pakistan, Central Asia and the Arab world.

This game has reached its limit. First, because ISIS presents a challenge to Saudi Arabia. ISIS says it is the “caliphate,” the center of Islam. Saudi Arabia believes it is the center. And, second, ISIS is threatening Muslims everywhere. Khalidi told me of a Muslim woman friend in London who says she’s afraid to go out with her head scarf on for fear that people will believe she is with ISIS — just for dressing as a Muslim. Saudi Arabia cannot continue fighting ISIS and feeding the ideology that nurtures ISIS. It will hurt more and more Muslims.

We, too, have to stop tolerating this. For years, the U.S. has “played the role of the central bank of Middle East stability,” noted Mousavizadeh. “Just as the European Central Bank funding delays the day that France has to go through structural reforms, America’s security umbrella,” always there no matter what the Saudis do, “has delayed the day that Saudi Arabia has to face up to its internal contradictions,” and reform its toxic ruling bargain. The future of Islam and our success against ISIS depend on it.