President-elect Donald Trump has set the foreign policymaking world on edge with his and his team’s repeated insistence that as president he will move the U.S. Embassy from Tel Aviv to Jerusalem. The goal: support Israel’s claim to the city as its “undivided, eternal capital.” By nominating David Friedman — who agrees with that position — to be ambassador to Israel, Trump apparently emphasizes this commitment.

The Israeli-Palestinian conflict has resisted resolution for decades. But Trump has insisted that “a deal is a deal” and that because he is “a negotiator,” he will be successful where others were not. In this case, presumably Trump plans to offer the Palestinians compensation to accept Israel’s claims to Jerusalem.

But it is not that simple.

The “let’s make a deal” approach assumes that each negotiating party has a series of material things that can be traded off. In this approach, both sides understand they will be better off with more than they currently have.

But that doesn’t apply to a place like Jerusalem, or to conflicts like it. Over time, territorial conflicts between ethno-national communities have become more about ideological and emotional attachments than about material interests. Recent research shows that groups can’t trade off material gain against territory that they consider to be part of the national homeland — territory that’s important to everyone who identifies with that ancestral homeland, wherever they actually live. Jerusalem is a prime example: Its existence is loaded with cultural, spiritual, religious and national meaning.

Jerusalem’s layered history is so important to both Jewish and Muslim religious practice as immovable “sacred spaces” that even when Israeli and Palestinian leaders hold similar attachments, they can’t decide its disposition alone. They must account for the emotional commitments of publics outside the Middle East.

Here’s why Jerusalem is so important for Jews

For Jews, Jerusalem is the site of both some of the greatest moments in their religious and national history and the place where Judaism was consolidated in a single structure, the Temple. Jewish religious traditions say that Abraham bound and nearly sacrificed his son Isaac on Mount Moriah in Jerusalem. Other biblical events took place there as well. Some Jewish interpretations contend that that’s also where Jacob dreamed of a ladder connecting heaven and earth.

Mount Moriah became the site of the Temple Mount, where both temples were built. These were the center of Jewish political and religious life until the Second Temple was destroyed around 70 C.E. The Western Wall is what’s left of that structure, which held up the platform on which the temple stood – and is thus the holiest available site of Jewish prayer.

During prayer services outside Jerusalem, Jewish congregations face toward Jerusalem. The city itself is mentioned during several liturgies. Many Jews end the Seder, or ritual meal, that’s at the center of the holiday of Passover by saying “Next year in Jerusalem!” And a community-wide day of mourning called Tisha B’Av commemorates different moments of disaster in Jewish history, including the destruction of both temples.

In secular history, Jerusalem is where David established the capital of his Jewish kingdom. His son Solomon maintained the city and built the First Temple. That’s why, when Zionism emerged in the late 19th century, Zionists focused especially (though not only) on Jerusalem. It was, for example, a major military objective during the 1948 war.

After Israel was established, it held only the western portion of the city, while Jordan controlled the eastern part, which included the Old City and the most important holy sites. But Israel captured the entire city during the 1967 war. Nationalism that mixes both secular pride and religious messianism quickly spread across the Israeli political spectrum, so that even many on the left insisted that Jerusalem must not be given up. In 1980, the Knesset, Israel’s parliament, passed a Basic Law: Jerusalem, which formally declared that “Jerusalem, complete and united, is the capital of Israel.”

Here’s why Jerusalem is so important for Muslims and Palestinians

Much like religious Jews, religious Muslims often see territory as infused with religious meaning. That means the holy sites in the city exist as an Islamic trust (waqf) that belongs to God.

Because Islam sees itself as the culmination of the monotheism in Judaism and Christianity, Jewish historical sites matter to Islamic history as well. But Jerusalem matters in other, more specifically Islamic ways. The first qibla, the direction that Muslims face during prayer, was Jerusalem; only later did Muslims turn toward Mecca.

To Muslims, the area that Jews call the Temple Mount is the Noble Sanctuary. Mohammad journeyed there one night to lead a prayer service with other prophets, a service which the al-Aqsa Mosque was built to commemorate. From there, Mohammad was carried to heaven. The Dome of the Rock mosque, which sits above the Western Wall, was built where Mohammad ascended. These sites and rituals have made Jerusalem the third-holiest city in Islam.

Islamic rulers held Jerusalem between 638 and 1917, except when it was briefly captured and controlled by the medieval Crusaders. This long rule cemented the city’s importance as part of Islamic community identity.

Most Palestinians are Muslim. But they consider Jerusalem significant for reasons beyond the religious ones. Muawwiyah, the first Umayyad caliph, took that title in Jerusalem as a way of tying his political-religious leadership to Muhammad.

When Palestinian nationalism emerged as a political movement in the 19th century, the city was part of its symbol of identity. The more the Zionist leadership in Mandatory Palestine treated Jerusalem as significant to their movement, the more important it became to Palestinians as a symbol of their own nationhood.

The 1988 Palestinian Declaration of Independence, for example, explicitly refers to Jerusalem as the capital of the state of Palestine. For Palestinians, then, Israeli control of Jerusalem is a daily reminder of the occupation and a barrier to their own self-determination.

None of this means Jerusalem’s status must forever be disputed

Some scholars have shown that territory once thought indivisible can indeed be divided. That happened, for instance, in Northern Ireland. But any approach must pay attention to the histories and memories of Jews, Israelis, Muslims and Palestinians at large.

Past negotiators have taken this into account. For instance, at Camp David in 2000, negotiators made detailed suggestions both about how to allocate sovereignty and authority and about each side’s demands that Jerusalem be its capital. And at the Jerusalem Old City Initiative, researchers have worked to precisely demarcate religious and political authority.

Sacred sites, collective memories, symbols of national identity: These are much harder to haggle over than real estate. Moving the U.S. Embassy will have to take into account these rival interpretations of the city if the Israeli-Palestinian conflict is to be resolved.

Brent E. Sasley is an associate professor of political science at the University of Texas at Arlington. Find him on Twitter @besasley.