How can America top its success helping Arab countries make peace with Israel? Well, witness Tuesday’s Gulf Cooperation Council summit in Riyadh.

Although details are murky, a new pact opens sea, land, and air borders between Saudi Arabia and Qatar and essentially ends a damaging dispute that loomed over the region for nearly four years.

While the longevity of the new pact remains to be seen, the fact that the emir of Qatar, Mohammed al Thani, flew to Saudi Arabia Tuesday and was greeted there by Crown Prince Mohammed bin Salman, known as MbS, is breathtaking.

All the more so because one guest at the table in Riyadh is Jared Kushner, President Trump’s son in law, a close friend of MbS, and a scion to a real estate family with businesses in Doha. Mr. Kushner played a major role in bringing the warring Arabs together.

As a first sign the pact is more than just pomp and circumstance, Qatar-based Al Jazeera ran a piece on Monday singing the praises of the Saudi capital’s modernity and beauty.

Such gestures would have been unthinkable at any time after 2017, when Saudi Arabia, the UAE, Bahrain, and Egypt severed ties with Qatar and revoked its membership in the Gulf Cooperation Council. The Saudi-Qatari border was sealed. Al Jazeera hurled accusations against the four countries while its competition, Saudi-based al-Arabiya, mercilessly attacked Qatar.

In a visit to Doha during that time, I heard endless stories of Saudi indecency, including most prominently a tale of a herd of Qatari camels that, traveling through the desert, got caught on the Saudi side. Unable to cross the sealed border and walk back home, the camels were left to die.

The dispute, of course, was about much more than the camels. The Saudis and their partners accused Doha of cooperating with Iran. Egypt was concerned about Qatar’s support of their top enemy at home, the Muslim Brotherhood. Everyone in the Arab world was angry at Qatar’s Al Jazeera. That most influential Arabic-language medium stirred up anti-authoritarian feelings across the region, where public unrest threatens regimes and heightens instability.

The dispute is also personal. As an Arab diplomat, a frequent visitor to Gulf capitals, told me at the time, three young royals with new powers revived and intensified ancient tribal rivalries. Riyadh’s MbS and his Abu Dhabi partner, Emir Mohammed bin Zaid (MbZ), united against Mr. al Thani, ignoring their elders’ call to cool passions down.

In that reading, personal enmities trump similarities among Gulf states. While publicly shaming each other, the three young royals employ similar strategies in attempts to modernize.

Beneath the glitz of Doha, Dubai, and Riyadh, civil rights are slightly improving, economic freedoms are slowly cropping up, and rigid traditions are giving way to Western lifestyles. In their struggle to diversify petro-economies, the Gulf countries pay huge sums to import Western and Asian scientists, academics, doctors, and art experts who help them compete in the 21st century.

Plus, too, the Gulf states are American allies. The Saudis and Emiratis, which recently acquired major American arms systems, battle Iran and their own extreme Islamist political forces. Qatar hosts the largest American military base in the region.

The Gulf dispute, though, was a major headache for America. Banned from Saudi air space, the Qataris flew over Iran, allowing Tehran to collect a fee and harming Mr. Trump’s drive to isolate the Islamic Republic economically. Doha, meanwhile, allied with Turkey in backing the Muslim Broethrhood.

For Qatar, winding down its Muslim Brotherhood ties is unlikely. That could remain a source of GCC discord. The Qataris, adept at playing all sides against the middle, will try to leverage these ties to offer diplomatic mediation between Washington and anti-American Islamists.

They already do it. In Doha, I asked a top official about Qatar’s support of Hamas, the Gaza-based Muslim Brotherhood offshoot. His answer: “Do you think we could deliver aid to Gaza without Israel’s green light?” Indeed, each time Gaza militants renew attacks on Israeli towns, Prime Minister Netanyahu facilitates the arrival of a Qatari envoy who, with the aid of cash-filled suitcases, convinces them to stop.

And now there’s even talk of Doha joining the Abraham Accords or at least renewing the near-official ties it once maintained with Israel.

Why now? After all, since 2017 America (and Kuwait) have endlessly and unsuccessfully tried to end the GCC dispute. How is it that while Vice President Biden threatens to cool down America’s ties with Saudi Arabia over the Khashoggi assassination, Qatar manages to overcome its animosity towards Riyadh.

The answer is Iran. The Sunni GCC members fear the renewal of President Obama’s call on them to learn how to “share” the region with Shiite (and, more importantly, meddlesome, belligerent, dangerous and anti-American) Iran. When Tehran was in America’s crosshairs, they could afford indulging in petty disputes. No longer.

Twitter @bennyavni