BEIRUT, Lebanon — For the last four years, President Trump’s close relationship with Saudi Arabia meant that there was seemingly nothing its de facto ruler, Crown Prince Mohammed bin Salman, could do to earn a rebuke from the White House.
Saudi bombs killed civilians in Yemen, Saudi activists went to jail, and Saudi agents dismembered the dissident Saudi writer Jamal Khashoggi in Istanbul. None of it shook Mr. Trump’s commitment to the kingdom as a reliable partner against Iran and an important purchaser of American weapons.
Now Saudi Arabia is bracing for a new American leader who has vowed to end support for the Yemen war, penalize human rights violations and treat Saudi Arabia like “the pariah that they are.”
“It is past time to restore a sense of balance, perspective and fidelity to our values in our relationships in the Middle East,” President-elect Joseph R. Biden Jr. told the Council on Foreign Relations last year when asked about Saudi Arabia. “We will make clear that America will never again check its principles at the door just to buy oil or sell weapons.”
The difference in tone is stark, and Prince Mohammed may have to accept that unless he changes his ways he is unlikely to be as welcome at the White House as he was under Mr. Trump. Experts said they did not expect a break with the kingdom, but pressure from a Biden administration could push Riyadh to temper its more reckless behavior.
“There are a lot of reasons for this relationship to continue — it has a lot of value for both sides — but it simply cannot continue in the way it has for the last four years,” said Tamara Cofman Wittes, a senior fellow in the Center for Middle East Policy at the Brookings Institution. “There have been a series of violations of the rules between friendly governments, a violation of norms.”
Saudi officials have played down the exceptional ties between Mr. Trump and the kingdom, instead emphasizing the nearly eight decades of cooperation between countries.
“Our relationship is far deeper than just one Saudi leader or one American president,” Princess Reema bint Bandar al-Saud, the Saudi ambassador to Washington, said in a video address to the National Council on U.S.-Arab Relations on Wednesday.
Saudi Arabia’s regional power and its growing global prominence — it will host the virtual Group of 20 summit in Riyadh this weekend — make it an important American partner, she said.
“As our economic, social and cultural reforms strengthen the kingdom, we’ll be even better positioned as the most dependable U.S. ally in the region,” she said.
Mr. Biden could find that he needs Saudi Arabia to help build regional support for a new Iran strategy, to stabilize oil markets or to help restart peace talks between Israel and the Palestinians. A Saudi offer to normalize relations with Israel could provide leverage to get concessions for the Palestinians and raise the kingdom’s standing in Washington, although Saudi and Israeli officials have said such a step is not imminent.
Mr. Trump’s presidency has tracked closely with the rise of Prince Mohammed, 35, whose father, King Salman, ascended the Saudi throne in 2015 and gave his son oversight of the government’s most important portfolios, including defense, oil and economic policies.
Prince Mohammed became crown prince in 2017 and cultivated a close relationship with Mr. Trump’s son-in-law and senior adviser, Jared Kushner, often meeting him privately in Saudi Arabia and exchanging messages on WhatsApp.
His international standing took a beating when Saudi agents killed Mr. Khashoggi inside the Saudi consulate in Istanbul in 2018, a crime the C.I.A. said Prince Mohammed had likely ordered. Prime Mohammed has denied ordering the killing or having any prior knowledge of it.
Last year, the Justice Department accused two Saudi men of spying for the Saudi government as employees of Twitter.
Through it all, Mr. Trump refrained from criticizing Saudi Arabia while supporting it in ways that alarmed officials in other branches of government. He applauded the blockade of Qatar, which hosts a large American air base; vetoed a bipartisan resolution that would have ended American support for the Yemen war; and said it did not matter whether Prince Mohammed had ordered Mr. Khashoggi’s killing because the Saudis opposed Iran and bought lots of American weapons.
Analysts said Mr. Trump’s support had enabled Prince Mohammed’s riskier moves, and that a new tone from the White House could have the opposite effect.
“I think the support from Washington emboldened him and took away many of the guardrails that ought to have been there,” said Rob Malley, the president of the International Crisis Group. “Biden has been very clear about Yemen, Iran and human rights. Those are three areas where you are likely to see a shift from the present.”
Officials on Mr. Biden’s transition team declined to comment, not wanting to appear to conduct foreign policy while another president was still in charge.
In Yemen, the United States has helped Saudi Arabia and its allies with aerial refueling of jets, intelligence and billions of dollars in arms sales. United Nations officials have called the war the world’s worst humanitarian crisis, and Saudi airstrikes have killed large numbers of civilians and destroyed key infrastructure.
The Saudis blame Yemen’s Houthi rebels, who are backed by Iran, for causing the crisis and for blocking efforts to end the war.
“We’ll continue to support a political solution in Yemen, but always defend our national security,” Princess Reema said.
Saudi Arabia shared Mr. Trump’s deep animosity toward Iran and supported his withdrawal from the international nuclear deal brokered under President Obama.
Mr. Biden has said he would rejoin the agreement as long as Iran also comes back into compliance, although Iranian and American political realities could make it impossible to restore the original deal.
Princess Reema called for international pressure to get Iran to return to negotiations, but said the goal should be a more sweeping deal that prevents Iran from acquiring nuclear weapons, stops its support for militant groups and ends “its destabilizing behavior in the region and the world.”
While Mr. Trump chose not to punish American partners for human rights violations, Mr. Biden has said that Saudi Arabia would no longer have a “dangerous blank check” and that the United States would “insist on responsible Saudi actions and impose consequences for reckless ones.”
That position has raised hopes among associates of the clerics, activists, businessmen and members of the royal family who have been detained during Prince Mohammed’s rise that Mr. Biden could press the kingdom for their release.
“I hope that Saudi officials realize that they need to restore their image and do things without waiting for anyone to pressure them,” said Alia al-Hathloul, whose sister, Loujain al-Hathloul, is on trial in Saudi Arabia on charges that human rights groups say are meant to punish her for her activism.
But Ali Shihabi, a Saudi writer and analyst, said United States pressure on issues inside the kingdom would likely hit a wall with Prince Mohammed.
“In Saudi Arabia, he has to be seen as strong and not buckling to Western pressure, otherwise that will weaken him on other fronts, where he is pushing through difficult reforms,” Mr. Shihabi said. “Obviously, Saudi would like to repair the relationship, but Riyadh understands that it may take time.”