President Trump's declaration of Jerusalem as the capital of Israel and vow to move the U.S. Embassy there drew a mix of jubilation and anger from members of Philadelphia's Jewish and Muslim communities Wednesday.

Trump said the move was necessary for achieving peace, casting it as a simple "recognition of reality" and giving assurances that the decision was not a departure from the United States' commitment to facilitating peace talks in the Middle East.

Some supporters applauded Trump for doing what his predecessors did not. But many Jews and Muslims alike expressed concern that the president's decision  will spark violence in an already unstable region and threaten the possibility of a two-state peaceful solution.

"Of course many of us would love Jerusalem to be announced the capital, but at what cost?" asked Rabbi Larry Sernovitz of Nafshenu, a progressive congregation in Cherry Hill. "If we want peace for Jerusalem, which is always what we've wanted, this seems counter to the objectives we're looking to meet. This is not the time to be playing with people's lives."

Jerusalem is sacred to three major religions. Trump's move reverses 70 years of  U.S. policy. His power to move the embassy comes from a 1995 act passed by Congress that recognized Jerusalem as Israel's capital and said the U.S. embassy must be moved there by 1999. But President Clinton used a waiver to extend the life of the U.S. embassy in Tel Aviv by six months, and every president since has done the same every six months. Now, the Trump administration has said  the president will sign the waiver for the next six months, because moving the embassy will take several years.

Recognizing Jerusalem as the capital fulfills one of Trump's campaign promises. Leaders in the Middle East along with others from Pope Francis to British Prime Minister Theresa May have condemned his decision.

The decision "prejudges one of the most sensitive issues in negotiations and isolates the United States internationally," said Michael Merryman-Lotze, Middle East program director at American Friends Service Committee, a national peacebuilding organization based in Philadelphia with offices in Israel and Palestine. "It kind of takes the U.S. out of play as a negotiator of a solution to the conflict."

Noting historical instances of protest and unrest in Jerusalem, he called Trump's decision "extraordinarily reckless."

Mazem Khalil, a Palestinian-American activist in Philadelphia, scoffed at Trump's claim that the move would bring peace and security. His response to Trump's declaration was simple:

"We existed there, we've been there, and we're going to still be there," he said. "We're not going nowhere, simple as that."

The news divided Jewish communities that have long split on the Israel-Palestine conflict, often along liberal and conservative political lines. A protest was planned for 4 p.m. Friday at JFK plaza. Meanwhile, others supported the president's decision.

Rabbi Albert Gabbai, who has led Mikveh Israel congregation in Center City for 30 years, called the day "jubilant."

"Many presidents before promised and they didn't deliver. This one promised and he delivered," said Gabbai, who will attend a conference of Orthodox rabbis in Jerusalem at the end of December. "They're going to threaten violence but you should not be held to blackmail."

In Yardley, students at Abrams Hebrew Academy attended a 1 p.m. assembly to watch Trump's speech, at times erupting into applause.

"I think they understood they were watching history today," said Rabbi Ira Budow, the school's director. "After 22 years of trying to do it one way and not recognize Jerusalem for the sake that something good would come from the non-recognition, finally someone stood up to the plate."

Steve Feldman, director of the Philadelphia Chapter of the Zionist Organization of America, watched a live feed of celebrations at the Western Wall following the speech. He called claims that the decision will lead to violence "disingenuous.

"It's a lack of recognition of the incitement every day," he said. "Do we want everybody to be held up and nothing to progress?"

The decision will sharpen the divide among Jews who fall on different sides of the issue, predicted Philadelphia-based Rabbi Linda Holtzman, a member of Jewish Voices for Peace. She and others also said the announcement could have precedent-setting implications.

"The idea of making it easier for Israel to annex more land is something that even many people who are deeply supportive of Israel are trying very hard not to encourage," she said.

That could upend international precedent, noted Marwan Kreidie, executive director of the Philadelphia Arab American Development Corporation.

"The whole post-World War II world consensus is we don't allow war to dictate the acquisition of territory," he said. "If we accept Israel's annexing of a place that they took through armed conflict, then what's wrong with the Russians taking Ukraine? What's wrong with other people taking land by force?"

Like others opposed to the decision, Kreidie viewed the move as a play to evangelical Christians in Trump's right-wing base rather than a step towards peace.

"Remember, Jerusalem is a special city," Kreidie said. "It's a city that's holy to three religions. It's supposed to be the city of peace. You don't give it to one side."