By Ari Harow

As Jews around the world gather on Tuesday to lament the destruction of Jerusalem by the Romans, and the millennia of exile that ensued, it is important that we take a moment to contemplate why we continue to mourn even after all of these years. For the Jewish people, Jerusalem is not merely a geographic locale or even a strategically located capital city - it is the basic justification for our existence as a nation.

What drove Jews over such a long time and across the vast Diaspora to mourn for Jerusalem for two thousand years was the belief that Jerusalem eternally encompassed our collective hope and dream. It was the loss of Jerusalem we cried for, and it was Jerusalem - Zion - that drove our national rejuvenation. What differentiated the Jewish Diaspora from all others was a common goal that transcended any one segment of the population.

A national ethos greater than any one individual is a basic necessity for a nation's survival. Can we imagine the United States of America without its Constitution and its Bill of Rights? Or Britain without its monarchy?

Of course not. That is because these are the essential elements that are at once both the emblem and the justification of these states' existence.

It is said that upon hearing that the Jews still (in 19th century France) mourn every year for the destruction of their beloved Jerusalem, Napoleon Bonaparte declared : "If the Jews are still crying after so many hundreds of years, then I am certain the Temple will one day be rebuilt!"

AS WE move forward in our quest for peace it is imperative that a united, undivided Jerusalem remain in our hands as well as in our hearts. The miraculous return of the Jewish people to Jerusalem after 2,000 years in exile is a realization of Napoleon's Tisha Be'av prediction.

Since Tisha Be'av 1967 we returned to lament at the footsteps of the destroyed Temple. This historic seismic event was a watershed moment which jolted Jews around the world and reminded us how vital Jerusalem is to the Zionist cause. Natan Sharansky has described on numerous occasions how Israel's victory was perceived by Jews in the USSR: "The Six Day War in Israel reconnected us with our people, with our country and history, and gave us pride for being Jewish. We discovered our identity and this empowered us to fight for our freedom."

We know that in the weeks and months ahead, it is likely that Prime Minister Binyamin Netanyahu will be faced with critical choices that will affect all of us who live in or care deeply about Israel. We trust that he will make the right decisions that ensure our vital security interests will be protected. Most importantly, however, we hope that Netanyahu follows the lead of his predecessor Menachem Begin who found himself in a similar situation a few short decades ago.

During the historic Camp David Summit, US President Jimmy Carter informed Begin that he would like to discuss the issue of Jerusalem. Carter asked him to consider a division, or internationalization of Jerusalem. Begin flatly refused Carter's request. When he was asked by the president why he refused on the spot without taking any time to consider this option, Begin replied by telling the story of Rabbi Amnon of Mainz who was pressured incessantly by the bishop of that city to convert to Christianity. After taking three days to think about it Rabbi Amnon returned to the bishop and turned down his offer. He was so overcome with guilt for having even contemplated the offer that he asked the Bishop to remove his tongue for uttering those words of doubt. The bishop responded by telling Rabbi Amnon that he would not cut out his tongue, rather for returning one day late Rabbi Amnon was cruelly tortured, his limbs amputated one by one.

Three days later, despite his terrible pain, Rabbi Amnon asked to be brought to his synagogue for Rosh Hashana. He was placed in front of the Holy Ark and there he uttered his famous prayer that has become the centerpiece of the High Holy Day liturgy - Un'taneh Tokef, Who shall live, and who shall die - and there he passed.

When Begin finished the story, he turned to Carter: "There are some things in life, Mr. President, that a Jew cannot even think about - and relinquishing Jerusalem in any way, shape or manner is one of them."

On this Tisha Be'av day, as we approach direct talks with the Palestinian Authority, it is imperative that we state loudly and clearly that Jerusalem is our heart and soul, our national raison d'être. Guaranteeing a united Jerusalem without one iota of hesitation or equivocation is not a matter of choice, but rather a national obligation.

This piece was initially published in the Jerusalem Post.

The writer served as the director of Prime Minister Binyamin Netanyahu's bureau and is a public affairs and international business strategic consultant.