President Donald Trump is announcing Wednesday that the U.S. officially recognizes Jerusalem as the capital of Israel, and that the State Department will begin the process of moving the embassy to Jerusalem from Tel Aviv.

It might be unclear at first why that policy change is so important. Jerusalem is, after all, the de facto capital of Israel. The Israeli parliament (Knesset) is there, as are the prime minister’s office, the president’s residence, the Supreme Court, and all of the executive agencies. Israelis consider Jerusalem their capital whether or not the U.S. recognizes it as such. As a practical matter, the change is symbolic. But as such, it is still extremely important.

To understand why, it is important to understand the history of the city. The Old Testament describes in 2 Samuel 5 how King David conquered the city and made it his capital, over 3000 years ago. It later describes in 1 Kings 8 how David’s son, King Solomon, built the Holy Temple and installed the Ark of the Covenant there. Since then, Jews have always faced Jerusalem in their daily prayers. It is the center of the Jewish faith and the core of Jewish history.

The Bible also tells the story of how the Jews were exiled from Jerusalem by the Babylonians, and later returned to rebuild the Temple. Another exile happened after 70 A.D., when the Romans destroyed the Second Temple and the city itself. Still, many Jews remained, and Jews worldwide prayed for 2,000 years for a return to “Zion.” Jews have been the largest ethnic group in Jerusalem for nearly 200 years, and a majority since the mid-nineteenth century.

Jerusalem is also holy to Christians and to Muslims, though it is less central to either. And under Israeli sovereignty, all religions have enjoyed the freedom to worship at their respective holy sites. The Temple Mount — or Haram ash-Sharif, to Muslims — has only been closed when there are imminent security threats, as radicals have sometimes used that holy site to attack Jews worshipping at the Western Wall — the last remnant of the Temple — below.

Jews began returning to the region in large numbers in the late nineteenth century as part of the Zionist movement, which aimed to re-establish Israel as a modern state, and as a refuge for the persecuted Jews of Europe. In 1917, the British government backed the establishment of a Jewish “national home” in what was then called Palestine (though the Arabs of the region did not call themselves Palestinians), in lands under British control since World War One.

The Jewish community of Jerusalem had, by then, expanded beyond the Old City and developed neighborhoods to the west. In 1947, the United Nations voted to approve the partition of Palestine west of the Jordan River into two states — one Jewish, one Arab. Jerusalem was to be an international city, not under the control of either side. The Jews accepted the plan and declared independence in 1948; the Arabs rejected the plan and declared war instead.

During that war, Arab forces fought to sever the connection between the Jewish community in Jerusalem and the Jewish communities further west. There was only one road to Jerusalem, and it was constantly under attack. In the Old City, Jewish fighters were eventually overrun by Jordanian troops — which, trained by Britain, were the Arab world’s best. Jordan occupied the Old City and flattened the Jewish quarter, ethnically cleansing its inhabitants.

From 1948 to 1967, Jerusalem was divided into two parts. On the western side, Israel established its capital amidst a modern city. On the eastern side, Jordan governed the Old City and the surrounding Arab neighborhoods of the West Bank. There was never any discussion of establishing a Palestinian state in the West Bank or a Palestinian capital in Jerusalem. Jews were denied access to the holy sites of the Old City, especially the Western Wall.

In the Six Day War of 1967, Israel — under direct threat of destruction by the surrounding Arab states — won a surprise victory and took control of the Sinai peninsula, the West Bank, and the Golan Heights. Israeli troops also conquered all of Jerusalem, reuniting it and liberating the Old City. But the Arab states still refused to negotiate with Israel, and most countries declined to place their embassies there for fear of antagonizing the Palestinians.

In the 1990s, when formal negotiations began between Israel and the Palestinians, Jerusalem was one of the most difficult issues — more difficult than the questions of borders and Palestinian refugees. Though Congress passed the Jerusalem Embassy Act in 1995, it gave the president the power to sign a waiver every six months delaying the embassy move. The idea was to preserve the status quo in Jerusalem so as not to jeopardize ongoing peace talks.

But as administration officials explained to reporters on Tuesday, after more than two decades, it was clear that recognition of Jerusalem as Israel’s capital was not a real obstacle to peace. It was clear to all that the western part of Jerusalem, at least, would be under Israeli sovereignty in any conceivable peace agreement. The idea that all of the city would be up for negotiation was little more than a concession to the most extreme Palestinian demands.

As such, recognizing Jerusalem as Israel’s capital and moving the U.S. embassy there is just a recognition of reality. But it is also a courageous decision, showing that the U.S. will stand with our allies regardless of terrorist threats.

President Trump’s decision also represents a guarantee of Israeli sovereignty in at least part of Jerusalem. As such, it represents the fulfillment of thousands of years of Jewish prayer, and over a century of Zionist efforts to establish and protect a Jewish state in the ancient homeland of the Jewish people.

It is no exaggeration to say that for Jews, recognition of Jerusalem as Israel’s capital is an event of almost Biblical significance. And we are witnesses to it.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He was named one of the “most influential” people in news media in 2016. He is the co-author of How Trump Won: The Inside Story of a Revolution, is available from Regnery. Follow him on Twitter at @joelpollak.