That has been a fact for millennia and it is good the United States finally recognized it, and this article from First Things about it is excellent.
Jerusalem was last a recognized capital city exactly 830 years ago, when in 1187 the Crusader Kingdom of Jerusalem surrendered the city to Saladin. The conqueror did not make the city his capital, and neither did any of the Muslim Arab, Mameluke, and Ottoman rulers who followed him. (Nor did a short-lived Crusader restoration, ruled from Acre.) Indeed, for centuries no ruler or state saw fit to declare the city a capital. No one that is, until 1948—when, despite near-universal condemnation, the newly established, fledgling, and fragile Jewish state, in the midst of a desperate war for survival against seven Arab armies, and barely hanging on to the western part of the city, declared Jerusalem its capital.
Why is it that the most famous city in the world, sacred to so many, was time and again shunned as a capital, even by the Palestinian-majority Jordanian kingdom that ruled its eastern parts from 1948 to 1967? Why is it that the 1947 UN resolution dividing the British Mandate territories into a Jewish and an Arab state saw fit to carve out Jerusalem expressly as a city to be under a “special international regime”—and most nations, including the US, have refused ever since to recognize Israel’s sovereignty over the city? Why did this attitude persist even after 1967, when Israel reunited the city and opened it, for the first time in its history, to free religious worship for all? Why was it that out of all capital cities in the world, good, bad, or ugly, only Jerusalem was denied recognition?
Because Jerusalem is much more than a city—it is also a powerful idea. It instills hope and fear. For many across the world, it is a symbol of redemption, but a celestial and spiritual redemption; for many others, it is a foreboding shadow, casting doubts about the purported trajectory of history from past darkness to future enlightenment. To all of these, the historic role of earthly Jerusalem has concluded, and having long been superseded, it now should, like Athens or Rome in their turn, be only a tourist’s or pilgrim’s destination.
But not so to the Jewish nation, for which even during eighteen centuries of exile, Jerusalem never became a thing of the past. It is present in virtually every daily and festive prayer, as well as in the declaration concluding every Jewish wedding: “If I forget thee, O Jerusalem, may my right hand forget its cunning; Let my tongue cleave to the roof of my mouth, if I remember thee not; if I set not Jerusalem above my chiefest joy” (Psalm 137). It is the place toward which all Jewish synagogues and graves around the world are oriented, and the namesake for the modern Jewish national movement, Zionism. Jerusalem has always remained so much at the heart of Jewish life and identity, that they cannot really be separated from each other. That is because Jerusalem is both the symbol and the actual place, assigned for that distinctive Jewish idea, of a redemption that will be spiritual as well as social and political, taking place within this world.
It is because of the nature of this deep and abiding connection that the description of Jerusalem as a city “sacred to the three monotheistic religions” can never do justice to the place it holds in Judaism. It certainly had an important role in the birth of Christianity and Islam; it holds a prominent place in their historic memory. But the role of Jerusalem to Jewish identity is different. It was possibly best described by John Selden, the eminent seventeenth-century English legal and political thinker as well as the greatest of Christian Hebraists, in his last published work, the massive treatise De Synedriis, on the judicial and political assemblies of the ancient Hebrews. Selden contested the prevailing view that Jews, long exiled and dispersed, were no longer a nation. He instead insisted that as long as the Jews adhered to their traditional laws, as part of their expectation to be restored eventually as a nation to their land and their city—not the heavenly city but the actual terrestrial Jerusalem—they indeed remained a nation.
Retrieved December 9, 2017 from https://www.firstthings.com/web-exclusives/2017/12/jerusalem-above-our-chiefest-joy