Something historic happened at a Manhattan hotel last weekend. The Western world is only now waking up to it.

A major Islamic pronouncement called the Rapprochement Communique was issued at the close of a two-day inter-religious conference titled, “Cultural Rapprochement Between the U.S. and the Muslim World.” The event was hosted by some of the most senior Sunni leaders from around the globe.

I got to be there. I’m still pinching myself.

The conference was organized by the Muslim World League, an influential Islamic organization based in Mecca and supported by the Saudi Arabian government. My consulting firm was retained to help identify NYC-area religious leaders who might want to participate. Many did, including Catholic, Jewish and evangelical laymen and clergy who were there among some 450 religious leaders from 65 nations.

The new communique calls on Muslims worldwide, among other things, to abide by the laws and constitutions of the nations where they live. That’s huge, as our president might say — it explicitly refutes those who wrongly insist that religious Muslims can’t also be fully integrated Americans. It also undercuts from on high extremists who tell Muslims that assimilation is heresy.

Statements at the conference were starkly unambiguous. I brought along a couple of normally cynical conservative friends to witness the proceedings, and their hopes were raised. One took to Twitter to let his friends know what he was hearing.

News of the communiqué is reverberating around Arab news outlets.

The theme of the conference was U.S.-Muslim cultural rapprochement, but it felt even bigger.

Maybe I’m naive, but my political history antennae were screaming with hope that something tectonic might be going on. With varying sects totaling 1.8 billion Muslims worldwide, peace is an extremely uphill task. But every effort toward it is welcome.

The secretary general of the Muslim World League, Muhammad al-Issa, traveled to Vatican City after the conference to meet with Pope Francis. That has to be a good thing.

Every man and woman of goodwill should pray for the communique’s success — that our children and grandchildren one day read about it in history books.

The world is weary of fighting. The killing has to stop.

William F.B. O’Reilly is a consultant for Republicans.