When asked by reporters during that flight back to the United States about why they had flown on the old Air Force One to England, Mr. Trump claimed he had wanted the troops stationed at the U.K. base to see the new plane. When pressed on why the window blinds had been directed to be shut on the flight from Turkey, Mr. Trump said that he knew of no specific threat, but described himself as under constant siege from Iran.

“I’m number one on their list, before you,” he told the reporters. “But if I go, you go. Right?

Mr. Trump and a number of his advisers have faced threats from Iran for years, especially after Mr. Trump, during his first term, ordered the killing of a powerful Iranian commander, Maj. Gen. Qassim Suleimani.

Mr. Trump’s advisers during the 2024 campaign privately told allies that they were given intelligence that Iran still hoped to harm Mr. Trump. That lead to the occasional use of decoy planes during the campaign. His staff at times put the candidate aboard a secret jet, without alerting the media, while his staff flew his private plane. The Biden administration increased security for Mr. Trump that summer after new intelligence about plots to kill Mr. Trump; a short time later, he faced an unrelated assassination attempt in Butler, Pennsylvania at an outdoor rally. There was a second unrelated attempt in September 2024.

The collective threats, which ranged from a prosecuted murder-for-hire plot by an Iranian proxy to the hacking of Trump campaign officials’ email and social media accounts, created a siege climate for the candidate and his aides. It led to fear, insularity and, at times, paranoia, that shaped how officials interacted with the Biden administration, which was responsible for allocating Secret Service resources, as well as with the media, and with other government officials.

After the Times reported about the security concerns in Turkey, and the fact that the Qatari jet lacked the same defensive capabilities as the older presidential aircraft, Mr. Trump was enraged by the leaks. The Justice Department issued subpoenas for grand jury testimony to the reporters who had been on the bylines of the stories, as well as some of their family members. Those subpoenas were withdrawn after a federal judge admonished federal prosecutors for the process involved.

Mr. Trump has continued to rage about information coming from his government that contradicts what he is telling the public, particularly about the war in Iran that he began on Feb. 28, according to multiple officials.

Katie Rogers, Erica L. Green and Doug Mills contributed reporting.