As Trump prepared to enter the White House, he took a sudden measure that unnerved officials in Beijing. On December 2nd, encouraged by the fiercest anti-China hawks among his advisers, including Steve Bannon, at that time his chief strategist, Trump took a telephone call from the President of Taiwan, Tsai Ing-wen, breaking with nearly four decades of American diplomatic practice. The U.S. has friendly relations with Taiwan, but Presidents since Ronald Reagan have avoided speaking directly with Taiwan’s President, because, as part of its “One China” policy, the U.S. formally recognizes only the Beijing government. Then, in an interview, Trump mused about giving up the “One China” policy and recognizing Taiwan’s government, in Taipei.

Chinese officials turned to the man that Kissinger had recommended to them: Jared Kushner. Kushner later told others that he took on the China portfolio reluctantly, after “clamoring” Chinese officials called Trump Tower and asked for him by name.

On December 9th and 10th, Cui Tiankai and Yang Jiechi, China’s top diplomat, visited Kushner at his office at 666 Fifth Avenue. Unlike officials from Japan and the United Arab Emirates, who were secretive about contacts with Trump’s transition team, the Chinese diplomats kept the Obama Administration informed. After visiting Trump’s transition team, Yang called the White House to report the encounter.

At times, Flynn and others joined the meetings. Laying out China’s hopes and ambitions for its relations, Cui urged the U.S. to expand military-to-military exchanges and to endorse the Belt and Road Initiative, a foreign infrastructure campaign intended to expand Chinese influence abroad. According to a participant in the discussions, Flynn welcomed the overture, praising the Belt and Road Initiative and saying that, although the U.S. had just one government at a time, he appreciated “beginning dialogue now.”

After Trump’s Inauguration, on January 20th, Kushner’s contacts with Cui intensified. They met again on February 1st, and, that day, Ivanka took her daughter, Arabella, to a lunar New Year celebration at the Chinese Embassy. Later that month, Kushner persuaded Trump to back off his threat to abandon the “One China” policy. Kushner also passed along proposals from Cui to Secretary of State Rex Tillerson, who made his first official trip to Beijing in March. During the visit, Tillerson startled China experts by adopting some of Beijing’s official phrases, including “mutual respect,” which is often interpreted as reinforcing China’s claims over disputed waters in Asia.

Kushner and Cui also met repeatedly to prepare for Trump’s first meeting with China’s President, Xi Jinping, on April 6th, at Trump’s Mar-a-Lago resort. Daniel Russel, who, until last March, was the Assistant Secretary of State for East Asian and Pacific Affairs, and is now a diplomat-in-residence at the Asia Society, in New York, said, “It was clear that heated arguments were taking place among the President’s advisers.” On one side, hard-liners, including Bannon, who has said he believes that China is “bent on world domination,” advocated a confrontational stance on trade and other issues. On the other, according to Russel, “Jared Kushner was described as adamant that Mar-a-Lago should be exclusively about bonding.” Russel continued, “We were told that the theory was to first establish a warm family friendship, using meals and Trump’s personal charisma.”

In the event, China overwhelmingly achieved its objectives: a soft-focus summit with regal photo ops and little talk of trade and other touchy subjects. It was also an auspicious occasion for the Kushner family. While Xi met with Trump, Beijing regulators approved three trademark applications from Ivanka’s company, to sell bags, jewelry, and spa services. Ivanka is also an adviser to the President, and her deals with the Chinese were hardly unusual. Since Trump assumed office, the Chinese government has approved scores of trademark applications by the Trump Organization.

Kushner was proud of his role in the summit, telling a person close to him, “People say we ought to do things the way they always have been done, with the same approaches. Somebody with more experience, tied to the old ways, may not have necessarily been able to pull off the Mar-a-Lago summit like we did.” He added that the officials who have criticized his approach to foreign affairs “usually get pretty uncomfortable when they’re not in control of something and it doesn’t go the way they want.”

By the spring of 2017, investigators in charge of evaluating whether to give Kushner a permanent security clearance had new information to consider. U.S. intelligence agencies aggressively target Chinese government communications, including Cui’s reports to Beijing about his meetings in the United States.

According to current and former officials briefed on U.S. intelligence about Chinese communications, Chinese officials said that Cui and Kushner, in meetings to prepare for the summit at Mar-a-Lago, discussed Kushner’s business interests along with policy. Some intelligence officials became concerned that the Chinese government was seeking to use business inducements to influence Kushner’s views. The intelligence wasn’t conclusive, according to those briefed on the matter. “I never saw any indication that it was successful,” a former senior official said, of Chinese efforts to compromise Kushner. The Chinese could have mischaracterized their discussions with Kushner. But the intelligence reports triggered alarms that Chinese officials were attempting to exploit Kushner’s close relationship with the President, which could yield benefits over time. “They’re in it for the long haul,” the former official said. (A spokesman for Kushner said, “There was never a time—never—that Mr. Kushner spoke to any foreign officials, in the campaign, transition, and in the Administration, about any personal or family business. He was scrupulous in this regard.”)

In March, 2017, Bill Priestap, the F.B.I.’s chief of counterintelligence, visited the White House and briefed Kushner about the danger of foreign-influence operations, according to three officials familiar with the meeting. Priestap told Kushner that he was among the top intelligence targets worldwide, and was being targeted not only by China but by every other major intelligence service as well, including those of the Russians and the Israelis. Priestap said that foreign spy agencies could use diplomats and spies masquerading as students and journalists to collect information about him. (An F.B.I. spokesperson declined to comment.)

Priestap and Kushner discussed some of Kushner’s contacts, including Wendi Deng Murdoch, the ex-wife of Rupert Murdoch. Kushner and Ivanka Trump had known her for about a decade, and she was a regular guest at their Washington home. U.S. diplomats and intelligence officials have long speculated about Wendi Murdoch’s ties to the Chinese government. Internally, some Chinese officials spoke about her in ways that suggested they had influence over her, the former senior official, who was briefed on the intelligence, said. Other officials said that the intelligence was inconclusive.

The allegations against Wendi Murdoch are complicated by her divorce from Rupert Murdoch. On January 15th, some of the allegations were published in the Wall Street Journal, which is owned by Rupert Murdoch. (A spokesperson for Wendi Murdoch said, “The idea that she is involved in anything covert is so absurd, it could only have come from an unnamed source.” A spokesperson for Rupert Murdoch said that Murdoch does not believe Wendi is a spy.)

When Kushner was briefed by the F.B.I., he saw little cause for alarm, according to a person close to Kushner. He had no doubt that China and other countries were trying to persuade him to do things or to provide information, but he was, despite his inexperience in diplomacy and intelligence, confident in his ability to navigate these situations. After all, he told others, New York real estate is not “a baby’s business.”