Will Dan Caine, Trump’s Pick for Joint Chiefs Chairman, Be Blunt or Hold His Tongue?

Lt. Gen. Dan Caine’s pocket-size copy of the Constitution is tattered and bound with green military tape.

He carries it with him routinely, including slipping it in his flight suit when he flew fighter jets in the Air Force. He had it on him on Sept. 11, 2001, when he was the lead aviator assigned to protect Washington after hijackers slammed commercial jets into the Pentagon and the World Trade Center.

General Caine’s loyalty to the Constitution and his reputation for adhering to ethical standards are major reasons the Senate Armed Services Committee is likely to give him a largely friendly reception on Tuesday as the members consider his nomination to become the chairman of the Joint Chiefs of Staff, the nation’s highest-ranking military position.

General Caine’s writings, coupled with interviews with some who know him, paint a portrait of a modest, thoughtful and personable officer with a reputation for integrity. That sets him apart from some other high-ranking administration officials who often appear to place their fealty to the president above all else.

“He has strong moral fiber,” said Raj Shah, who led a high-level Defense Department unit on innovation and has known General Caine for 20 years. He added, “He is one of the most humble, principled and strategic leaders I have known.”

But General Caine will still have to navigate some tough questions about whether he will give his best unvarnished military advice to President Trump or tell him what he wants to hear.

“We have to determine whether he has the professional skills to do the job,” Senator Jack Reed of Rhode Island, the panel’s senior Democrat, said in a phone interview. “But we also need to know whether he will stand up to the president and say if something is not lawful.”

The hearing will be an exercise in needle-threading for the 35-year military veteran with a polished record, possibly the first of many as he tries to maintain credibility with Mr. Trump while staying true to military and ethical norms. It comes amid broad outrage over the administration’s careless handling of highly sensitive military plans for last month’s attacks in Yemen. Many outside experts have said the administration’s top national security officials ignored rules on handling such information in ways that could have risked the safety of the American pilots involved.

Defense Secretary Pete Hegseth, who shared the timing and targets of imminent military strikes against Iran-backed Houthi militants over the commercial messaging app Signal, has said he did not relay classified information. Mr. Trump has dismissed the controversy as a minor fumble.

Democrats on the committee are expected to ask General Caine whether he considers the information that was shared to be classified and whether he would have advised the use of secure government channels instead of a Signal chat that inadvertently included a journalist.

Nonetheless, they are unlikely to press him to directly criticize the administration’s actions for fear of irreparably harming his relationships with the president and Mr. Hegseth even before he takes office. They see the general as a potential guardrail against possibly rash or even illegal military actions by the Trump administration, and so want to preserve his influence.

General Caine, 56, who is stepping out of military retirement, faces a steep learning curve. By statute, anyone picked to be the chairman of the Joint Chiefs of Staff is supposed to have served as a combatant commander, as the vice chairman of the Joint Chiefs of Staff or as the top uniformed officer of the Army, Navy, Air Force, Marine Corps or Space Force — all four-star positions (General Caine retired with three). Mr. Trump has invoked a waiver to bypass that requirement.

An F-16 pilot with 150 combat flight hours, General Caine has a background in highly secretive intelligence and special operations assignments that stands out from those of previous nominees. In the three years before he retired from the military in December, he was an associate director for military affairs at the C.I.A.

General Caine has sprinkled self-insights and bits of advice in two blogs. Recurrent themes are his efforts to improve his communication skills, his pursuit of self-control and odes to fallen service members.

One of his favorite books, he wrote, is “The Daily Stoic,” a 405-page treatise about the virtues of self-mastery, perseverance and wisdom. Another is “Strength for Service to God and Country,” a book of devotions for those in the military or public service. He also recommended “The Four-Hour Work Week” by Tim Ferriss, a book on strategies to achieve one’s goals with less effort.

His Air Force nickname, which the president is said to relish, is “Razin Caine.” But the lifestyle he described in a 2020 blog post seems a model of discipline. He laid out a six-day workweek and this daily schedule:

Wake up to a 4:15 a.m. alarm; spend 45 minutes over coffee in reflection and Bible study; work out for an hour; listen to a half-hour of Bloomberg News or a podcast over a protein shake; work for 11 to 12 hours; and then bed at 9 p.m.: “67 degrees, dark room.”

He so far has eschewed public discussion of politics. Perhaps the closest he has come was a 2018 blog post, written during Mr. Trump’s first term, about the potential impact of tariffs the president was proposing. He linked to a webcast by a corporate leader who called for free trade, describing the issue as “fascinating.”

Mr. Trump and General Caine met only once before, in late 2018, when the president visited U.S. troops in western Iraq. But the meeting eventually took on political overtones. General Caine told the president that the Islamic State was not so tough and could be defeated in a week, not two years as senior advisers predicted, Mr. Trump recounted in 2019.

At a Conservative Political Action Conference meeting the next year, and subsequently since then, Mr. Trump has said that General Caine put on a Make America Great Again hat while meeting with him in Iraq. General Caine has told aides he has never put on a MAGA hat.

His business career is another contrast with previous nominees. From 2009 to 2016, as a part-time member of the National Guard, he founded or led a string of companies, drawing partners, employees and customers from his wide network of military contacts. Most were small aviation-related firms with fewer than 25 employees.

The federal government hired one of his firms, Global Risk Reduction, to help put safety protocols in place at a biocontainment laboratory at Fort Detrick in Maryland. General Caine helped train lab employees in how to prevent, track, investigate and correct safety lapses, said Dr. James Lawler, the laboratory’s former chief medical officer.

“We all trusted Dan,” he said. “He is the kind of leader who comes into a room and the first thing he does, usually, is admit his own faults and mistakes, and then he listens to everybody else.”

Another company the general founded, called Patriot Technologies Group, provided air surveillance and support for U.S. armed forces training exercises. A pilot and two crew members employed by the company were killed when their plane crashed in a 2010 training session in Florida. General Caine, a lieutenant colonel at the time, was in another plane during the exercise.

The widows of the men who died sued the government, claiming that Air Force personnel on the ground had failed to warn the pilot of a thunderstorm that caused the plane crash. Daniel O. Rose, a lawyer who specializes in airline crash cases and who represented the widows, deposed General Caine as part of the case. He said he expected him to defend the Air Force personnel out of loyalty.

“I just couldn’t believe it when he started talking,” Mr. Rose said. “He really was calling it straight, calling the Air Force out. He really is just a stand-up guy.”

The government ultimately settled the case.

None of General Caine’s business ventures made him particularly wealthy, judging by a review of his property holdings and interviews with his friends. But after he retired from the military at the end of last year, lucrative work seemed in the offing. He became a venture partner at two investment firms and an adviser to a third, led by Josh Kushner, the brother of Jared Kushner, the president’s son-in law.

“He had been offered other military jobs, and he turned them down. He had moved on to the private sector,” said Mr. Shah, the co-founder and managing partner of Shield Capital, which hired General Caine before Mr. Trump chose him as his top military adviser.

“He was not looking for this job,” Mr. Shah said.

Julie Tate contributed research.