Hours after US president Donald Trump declared yesterday that the US would move its Israeli embassy to Jerusalem, US allies from Malaysia to Indonesia to France to Britain, condemned the move.

The unpopular decision reverses decades of American policy in the Middle East. Americans in Turkey, Germany, and through the region were warned by local US embassies to be cautious after the decision, and American children in Jordon told not to go to school. At least 22 were wounded during protests in Gaza and the West Bank, and militant group Hamas called Trump’s announcement a “declaration of war.

The decision is not popular at home, either. Trump’s own Department of Defense and Secretary of State tried to talk him out of it, according to multiple reports. Just 16% of Jewish-Americans favor unilaterally moving the embassy to Jerusalem, which Palestinians also claims as their capital, according to a survey of “American Jewish Opinion” taken in September. Overall, 63% of Americans oppose the move.

Trump’s decision is a “profound mistake,” Jeremy Ben-Ami, the president of J-Street, a “pro-peace, pro-Israel” lobbying group in Washington DC said Wednesday, echoing the words of French president Emmanuel Macron and many others.

So how did it happen? Trump’s decision is the latest example of how special interest groups, rather than US voters or long-term American diplomatic goals, can drive policy. Analysts say wealthy donors, influential lobby groups, and a far-right Christian fringe put pressure on a president eager to show he’s fulfilling his campaign promises.

A White House spokesman didn’t respond to questions about Trump’s rationale for making the move.

Donors Sheldon and Miriam Adelson

Just as deep-pocketed donors to the Republican party had a huge impact on the hastily-written tax reform bill that’s now being reconciled in Congress, they have put direct pressure on the US president to change US policy in Israel.

Most prominent are casino magnate Sheldon Adelson and his wife Miriam, the largest individual Republican donors in 2016, who coughed up $83 million. Adelson failed to back Trump initially in the Republican race, but made an abrupt about-face after the primary, earning the couple a seat at Trump’s inauguration.

Reuters/Brian Snyder Adelson and Ochsorn with ex-White House advisor Stephen Bannon at the inauguration, Jan. 20.

Moving the US embassy to Jerusalem has long been one of the couple’s goals—one that is particularly important for Ochsorn, some say, who was born in British-ruled Palestine. “There’s a theory that Miriam is the real driver on a lot of these issues,” said Michael Green, a history professor at the University of Nevada. She may be the one that “really has a greater ideological commitment” than her husband. Thanks to their donations, both the Adelsons can “pick up the phone and call the White House,” Green said.

Sheldon Adelson was waiting patiently for action on the move, a spokesman told Politico in April, but was “furious” in May, Axios reported, after Secretary of State Rex Tillerson expressed caution about relocation and said the president wanted to be careful not to impact the peace process.

In a sign of their displeasure, the couple so far haven’t donated enough to even crack the top 50 donors in the 2018 midterm races.

The couple had a private dinner at the White House on October 2, where they discussed the Las Vegas shooting the day before, but also pushed Trump on relocating the embassy, the New York Times reported (paywall). Adelson’s spokesman didn’t return requests for comment.

Pro-Israel lobbying groups and think tanks

The powerful pro-Israel lobby has spent tens of millions of dollars in the United States in recent years, hoping to influence Congress and the executive branch. Spooked by concerns that former president Barack Obama would be less supportive of Israel, donations by individuals and political action committees jumped in 2008, his first year in office. They hit a record of nearly $20 million in 2016.

The lobbying has been dominated for years by hard-line voices that don’t reflect how most American Jews think about Israel and Palestine, says J-Street’s chief of staff Daniel Kalik. In part in deference to these groups, and over the opposition of then-president Bill Clinton, Congress voted in 1995 (paywall) to move the US embassy by 1999, but included a caveat that would allow any president to delay the move indefinitely for security reasons.

Relocating the US embassy to Jerusalem is “pretty outside the mainstream in terms of a policy decision,” said Kalik. It is certainly not designed to get votes from American Jews, he notes, who make up just 2.6% of the US population and for the most part are progressive Democratic voters.

In recent years, US political candidates have tried to beat their competitors by seeing who could be more “pro-Israel” in the mold of these lobbies, in the hopes that it will give them more support financially and otherwise, Kalik said. The powerful American Israel Public Affairs Committee spends millions every year on lobbying:

AIPAC’s command over US politicians was evident last March, when presidential candidates Ted Cruz, John Kasich, Donald Trump and Hillary Clinton all spoke in person at AIPAC’s annual convention; Bernie Sanders recorded a video address for the event.

Sanders, the only Jewish candidate, offered some rare criticism of the lobby’s policies, saying, “When we talk about Israel and Palestinian areas, it is important to understand that today there is a whole lot of suffering among Palestinians and that cannot be ignored.” Peace, he said, would require compromise from “both sides.”

John Bolton may also have played a role in Trump’s decision. The former US ambassador to the United Nations and one-time advisor to Trump is on the board of directors of the Jewish Institute of National Security of America, an anti-Iran, pro-Israel think tank.

Bolton complained in late August that he was being shut out of White House discussions, after General John Kelly took over as Trump’s chief of staff. But Trump’s rationale on Dec. 5 for moving the US embassy seemed to come right from Bolton’s mouth.

“After more than two decades of waivers, we are no closer to a lasting peace agreement between Israel and the Palestinians,” Trump said, then listed the reasons why Jerusalem was the obvious capital of Israel, including that fact that is it home to Israel’s parliament. “It would be folly to assume that repeating the exact same formula would now produce a different or better result.”

Bolton made almost exactly the same arguments in a hearing to a Congressional committee last month (pdf). “If the Middle East peace process is such a delicate snowflake that the location of the US Embassy in Israel could melt it, one has to doubt how viable it is to begin with,” Bolton said.

Bolton was spotted at the White House today. He was there “because he is a friend of the president,” press secretary Sarah Huckabee Sanders said.

The Christian radical right

While pro-Israel lobbyists may have provided serious financial incentive, Trump’s support among Christian evangelicals, who voted overwhelmingly for him in the presidential election, provided additional pressure.

Most Americans, about 71%, identify as Christian, but only one-third of those call themselves “evangelical,” and evangelicals are divided on Jerusalem’s importance.

Some Christian evangelicals interpret the Old Testament’s description of Jerusalem as the capital of Israel 1,000 years before Christ as the sign of what is to come, as Gary M. Burge explains in the Atlantic. They “believe that promoting the importance of Jerusalem is one more building block in the fulfillment of prophecies that sets the stage for the Second Coming of Christ,” he writes.

Christian evangelicals put pressure on Trump to make the call and some rejoiced after the decision. “In the Six Day War Jews finally took sovereignty over Jerusalem, and it’s absolutely crucial in terms of biblical prophecy that they maintain control over that,” televangelist Pat Roberstson said Dec. 5, celebrating Trump’s decision.

Rene Omokri, founder of California’s “Mind of Christ Christian Center,” said he was now willing to die for Trump.

Trump didn’t provide any specifics about how soon the move would be made. But, as Israeli prime minister Benjamin Netanyahu pointed out today, by making the decision, Trump had already “made history.”