Already, many Israelis and Palestinians are buzzing about the prospect. Where would the embassy go? Would it straddle the line between West Jerusalem, which is predominantly Jewish, and East Jerusalem, which is predominantly Arab? Would it touch off street protests in Palestinian cities or a backlash among Arab allies like Egypt and Saudi Arabia?
“Jerusalem is a symbolic, emotional and real issue,” said Itamar Rabinovich, a former Israeli ambassador to the United States and president of the Israel Institute. “It matters to many Israeli Jews because it would indicate that the United States actually recognizes Jerusalem as Israel’s capital, which now it effectively does not.”
Which is why Arabs object so strenuously to such a move. “This is a sign that he’s going to side with Israel,” said Mustafa Alani, a scholar at the Gulf Research Center, a research organization with offices in Saudi Arabia and elsewhere. “If he does it, it’s going to be a wrong start for his relationship with the Arab world.”
The status of Jerusalem has always been one of the thorniest issues dividing Jews and Arabs. In 1947, the United Nations recommended that the city be declared a “corpus separatum,” meaning an international city, rather than incorporated into either the Arab or the Jewish states then being contemplated on the land between the Jordan River and the Mediterranean Sea. But in the war that followed its declaration of statehood in 1948, Israel captured the western portion of the city while Jordan seized the east.
Israel took control of East Jerusalem in its 1967 war with its Arab neighbors and annexed it, declaring that the city would remain whole and unified as its eternal capital (and later building many settlements in eastern neighborhoods that most of the world considers illegally occupied). The United States and most other countries refused to recognize the annexation and kept their embassies in or near Tel Aviv. The last two countries with embassies in Jerusalem, Costa Rica and El Salvador, moved out a decade ago.
Bill Clinton and George W. Bush both promised during their presidential campaigns to move the embassy to Jerusalem. Both later backed away from those promises, convinced by Middle East experts that doing so would prejudge negotiations for a final settlement between Israelis and Palestinians.
In 1995, Congress passed a law declaring Jerusalem to be Israel’s capital and requiring the embassy be moved there by 1999 — or else the State Department building budget would be cut in half. But the law included a provision allowing presidents to waive its requirement for six months if they determined it was in the national interest. So every six months, Mr. Clinton, Mr. Bush and eventually President Obama signed such waivers, fearing a violent response in the Arab world if the embassy moved.
“Every president who reversed his campaign promise did so because he decided not to take the risk,” said Dennis B. Ross, a longtime Middle East envoy who advised multiple presidents, including Mr. Obama. “Jerusalem has historically been an issue that provoked great passions — often as a result of false claims — that did trigger violence.”
Whether such advice might sway Mr. Trump is unclear. Despite Mr. Greenblatt’s declaration, another Trump adviser on the Middle East, Walid Phares, told the BBC that Mr. Trump would move the embassy “under consensus.” He later clarified that he meant a “consensus at home,” since no one could imagine a consensus including Arabs at this point.
Elliott Abrams, a former Middle East adviser to Mr. Bush, said Mr. Trump should follow through because even if East Jerusalem is eventually ceded to the Palestinians as the capital of their own state, no plausible settlement would deny West Jerusalem to Israel. “There is simply no reason not to put a U.S. embassy there,” he said.
The issue remains so delicate that the Obama administration went all the way to the Supreme Court to block a law passed by Congress allowing American parents of children born in Jerusalem to list Israel as their birthplace on their passports.
When Mr. Obama came to Jerusalem in September for the funeral of Shimon Peres, the former Israeli president and prime minister, the White House initially released a transcript of his eulogy that listed “Jerusalem, Israel” as the location of his remarks. A few hours later, it issued a “corrected” transcript that literally crossed out the word “Israel.”
The consulate currently in Jerusalem, run by the consul general, Donald Blome, a career diplomat, deals mainly with the Palestinians while the embassy in Tel Aviv, run by Ambassador Daniel B. Shapiro, an Obama appointee, handles relations with Israel. Mr. Trump could simply declare the consulate to be an embassy and move the ambassador’s home as a stopgap, but there are other logistical challenges.
The embassy’s 800-person staff could not fit in the consular offices near the Old City, nor in the large, fortresslike building that processes visa requests and is surrounded by stone walls and tall metal fences along the line that divides Jerusalem between Jewish and Palestinian residents.
Israeli Jews cite a long history in Jerusalem dating back thousands of years, and even many on the left who support a Palestinian state think the embassy should be housed there. Gilead Sher, who worked as a peace negotiator for Labor Party leaders, said, “It seems abnormal that the city, which is home to all of Israel’s governmental, legislative, judicial and national institutions, does not host foreign embassies.”
But Oded Eran, a retired Israeli diplomat now at the Institute for National Security Studies in Tel Aviv, noted that Israel has not invested “much political capital” in the matter because of “a sober assessment that few, if any, will move their embassy to Jerusalem.”
Indeed, with other perhaps more urgent priorities, Prime Minister Benjamin Netanyahu and his government have made little comment on the possibility since Mr. Trump’s election. “That has been a constant commitment by many administrations, and one would expect it will be acted on at the right time,” said Dore Gold, a longtime adviser to Mr. Netanyahu who just stepped down as director general of the Foreign Ministry.
Palestinian officials presume Mr. Trump ultimately will follow the course that his predecessors did and leave the issue to final-status negotiations.
“I don’t think he’ll move the embassy, and I don’t think he’ll legalize settlements,” said Saeb Erekat, secretary general of the Palestine Liberation Organization. “I’m confident we’ll work with President-elect Trump and his administration to achieve peace and to achieve the two-state solution.”