I’d venture to guess that most of what you heard about President Obama’s summit last week was wrong. To start, it wasn’t a “summit.” That term, coined by Winston Churchill, implies a meeting of heads of government. However, the most important Arab leader invited by Mr. Obama, King Salman of Saudi Arabia, stayed home, as did the rulers of the United Arab Emirates and Oman. King Hamad bin Isa al-Khalifa of Bahrain decided his time could be spent more productively at the Royal Windsor Horse Show outside London.

You also may have heard that the reason the leaders of the Gulf Cooperation Council (GCC) didn’t attend was that they were put off by the prospect of international travel. Trust me: Flying in one’s own customized jet is a lot less wearying than going coach.

It is true that by not showing up they were making a statement. But to say they “snubbed” the president, as several commentators did, is imprecise. They were demonstrating not disdain but distrust: They know Mr. Obama wants to convince them that the agreement he’s bending over backward to conclude with the Islamic Republic of Iran will help stabilize a Middle East that grows more chaotic by the day. They’re not buying it. So they sent envoys empowered only to say: “Thank you, Mr. President. I will convey your views to His Majesty.”

Negotiations with Iran were intended to prevent the world’s leading sponsor of terrorism from acquiring a nuclear weapons capability. At this point, they are veering toward providing Iran’s rulers with two paths to that capability: a slow but sure one if they abide by the agreement’s stipulations; a faster one if they violate their obligations — as they have in the past.

Whatever Iran does get under the agreement, the Saudis “will want the same,” as Prince Turki al Faisal, the former Saudi intelligence chief, acknowledged a few months ago. The Saudis can develop their own nuclear weapons program or they can purchase nukes — probably from Pakistan, which decades ago developed its own nuclear weapons thanks to Saudi largesse. The Sunday Times of the United Kingdom is now reporting that Saudi officials have already made that “strategic decision.”

Others in the region — the United Arab Emirates, the Turks, the Egyptians — are likely to follow suit. The result will be a “nuclear cascade,” which means the death of the nuclear nonproliferation movement. The irony here should not go unremarked: In 2009, not long after he had moved into the White House, Mr. Obama was awarded the Nobel Peace Prize for his “vision of and work for a world without nuclear weapons.”

A second justification for the Nobel Prize was Mr. Obama’s “extraordinary efforts to strengthen international diplomacy and cooperation between people.” In this regard, he has succeeded in an unexpected way: When it comes to the threat posed by Iran, the Saudis and other Arab countries have found common ground with Israel.

They all grasp what Mr. Obama will not: Iran is ruled by self-proclaimed religious revolutionaries who prefer power to peace, who command an expanding empire that already reaches deep into Iraq, Syria, Lebanon and Yemen (with weapons and money being sent to Hamas so it can launch more wars against Israel from Gaza), and who aim to weaken and ultimately defeat their neighbors — Sunni and Jewish alike.

An additional unintended consequence of Mr. Obama’s Middle East policies: The Saudis and other Arab rulers are now being incentivized to resume (or, in some cases, increase) their support of Sunni jihadis. The logic is not hard to grasp: If Iran is about to become militarily stronger, with tens of billions of dollars awarded as a nuclear agreement “signing bonus,” it makes sense to back forces willing to fight and, perhaps, contain Iran. That’s good news for al Qaeda and the Islamic State; bad news for just about everyone else.

Indeed, even as the not-quite-a-summit was proceeding without him, King Salman was meeting with extremist clerics, the kind American diplomats have for years been asking the royal family to marginalize. Foundation for Defense of Democracies Senior Fellow David Weinberg has reported that one of the preachers the Saudi monarch graced with his presence advocates slavery and preaches that the Islamic State is a creation of Zionists and “crusaders” (read: Christians). Another calls homosexuality an affliction that “seeks to strip man of his humanity” and “darkens and covers the soul.”

As Mr. Obama’s Gulf visitors were preparing to depart, a joint statement was issued. One prominent Washington pundit called it “surprisingly upbeat,” asserting that it gave the Arab nations an “unequivocal” American commitment to “deter and confront” any future aggression from Iran. I’d argue that, au contraire, the statement was mainly boilerplate and blather.

One example: The United States and the Gulf Cooperation Council expressed their “shared recognition that there is no military solution to the region’s armed civil conflicts, which can only be resolved through political and peaceful means.” The carnage in Iraq, Syria, Yemen, Libya and the Sinai are going to be ended through “political and peaceful means”? Really?

Another example (one that might seem to contradict the above): Mr. Obama promised that in the event of “aggression” or even “the threat” of aggression, the United States “stands ready to work with our GCC partners to determine urgently what action may be appropriate, using the means at our collective disposal, including the potential use of military force, for the defense of our GCC partners.” Does that sound like an “unequivocal” American commitment? Or does it sound like a jumble of diplomatic weasel words?

I think I know how it was read by most Arabs. In Tehran, however, I’d venture to guess it came across as enormously reassuring and rather amusing.