This September we’re commemorating 20 years since the 9/11 attacks on the United States.

Those of us who have been professionally involved in the study of the Middle East were shocked to learn that the vast majority of the terrorists who flew hijacked aircraft into the World Trade Center and the Pentagon did not come from Lebanon, Libya, or Syria, but rather from Saudi Arabia.

Across the world, many tried to understand the source of the rage that motivated the decision to attack the West. Looking into this question at the time, I discovered that in Saudi Arabia there were huge multinational charities propagating a movement representing an extreme form of Islam, known in the West by the name of its 18th century founder, Muhammad ibn Abdul Wahhab.

We in Israel had a particular interest in what they were doing, since one of their recipients was Hamas, a Palestinian group that advocated suicide bombings which were hitting our major cities.

I wrote a New York Times bestseller, Hatred’s Kingdom, which presented the evidence from captured documents.

Fast forward to 2021.

How much Saudi money is now going to Hamas? How much today reaches them? The answer is Zero.

In fact, Saudi Arabia is not giving a dime to any of the terrorist organizations.

Today the main countries funding Hamas are the Islamic Republic of Iran and Qatar.

What about the propagation of extremist ideologies? Back in 2001, the Muslim World League, headquartered in the Saudi Kingdom, was spreading the ideology that supported a new wave of global terror.

Yet today its secretary-general took a delegation to Auschwitz.

We are in a different world.

Today our collective challenge is the Islamic Republic of Iran and its proxies, which seek to re-establish Persian power in the framework of a renewed Safavid Empire.

That would bring the Iranian armed forces into most of Afghanistan, as well as Iraq and large parts of Syria.

Tehran is claiming much of the Arab Gulf as its sovereign territory.

The West’s attitude to Iran, however, is unclear.

The last time it made a nuclear deal with Tehran in 2015, what we call the JCPOA, it removed sanctions, leading to massive funds flowing to the Iranian treasury and then to its militia forces around the Middle East.

This must not happen a second time.

This is not about geo-politics alone.

Historically, Jews and Muslims have been cousins who surmounted their differences and reached a common language that brought us together. In the Middle Ages, Jewish religious scholars like Maimonides wrote in Judeo-Arabic.

Our religions are rooted in common concepts, especially the One-ness of G-d, which is called Tawhid in Arabic. Our concept has been enshrined in the Biblical verse: “Hear O Israel the Lord our G-d, the Lord is One.”

Our region gave birth to our religions and to the nations that today live with us.

We must embrace that history again and in doing so set the stage for a very different Middle East.