WASHINGTON — Navy Secretary John Phelan has abruptly left his post, the Pentagon announced Wednesday, a sudden departure that makes him the first head of a military service to leave during President Trump’s second term and the latest senior defense official pushed out amid a series of leadership shakeups.
The Pentagon provided no explanation for Phelan’s immediate exit. The announcement comes as the Navy is conducting operations tied to a fragile ceasefire in the Middle East, including a blockade of Iranian ports and actions against ships linked to Tehran, and while several carriers and other forces are deployed or en route to the region. Undersecretary Hung Cao, a 25-year Navy combat veteran, will assume the role of acting secretary.
Pentagon spokesman Sean Parnell posted on X that Phelan was “departing the administration, effective immediately.” Phelan’s office had posted about his recent activities on social media, underscoring how sudden the move was: he spoke Tuesday to a large audience of sailors and industry representatives at the Navy’s annual conference in Washington, met with reporters about his agenda, and hosted House Armed Services Committee leaders to discuss the Navy budget and shipbuilding plans.
Phelan had not served in the military or previously held a civilian leadership job in the Navy before President Trump nominated him in late 2024. Seen as an outsider, he was a major donor to Trump’s campaign and founded the private investment firm Rugger Management LLC. His biography also lists an advisory role with Spirit of America, a nonprofit active in backing defenses for Ukraine and Taiwan.
The Associated Press could not immediately reach Phelan for comment, and the White House declined to answer questions, instead sharing the Pentagon’s statement.
Phelan’s exit is part of a broader pattern of turnover at the Pentagon since Defense Secretary Pete Hegseth took office. In recent months Hegseth has dismissed multiple senior uniformed leaders, including the Army’s top officer Gen. Randy George. Earlier shake-ups in 2025 included the removals of Adm. Lisa Franchetti, the Navy’s top uniformed officer, and Gen. Jim Slife, a senior Air Force leader. President Trump also removed Joint Chiefs Chairman Gen. Charles Q. Brown Jr.
The Navy is managing a heavy global tempo as the leadership change occurs: multiple aircraft carriers are deployed or heading toward the Middle East, the service has maintained an elevated presence in the Caribbean as part of anti-drug operations, and it was cited by the administration as playing a key role in a high-profile operation in January involving Venezuelan leader Nicolás Maduro.
Hung Cao, who will serve as acting secretary, is a former special operations officer and career naval officer who ran unsuccessful Republican campaigns for the U.S. Senate and House in Virginia. He sought the Senate seat in 2024 against Democrat Tim Kaine, winning the GOP primary with Trump’s endorsement and speaking at the Republican National Convention.
Cao’s personal history includes fleeing Vietnam as a child with his family in the 1970s. During his Senate campaign he contrasted Vietnam’s communist government with the Biden administration and, in debate appearances, criticized COVID-19 vaccine mandates for service members and military efforts around diversity, equity and inclusion. In one debate exchange he said, when criticizing recruitment efforts, that ‘when you’re using a drag queen to recruit for the Navy, that’s not the people we want,’ and added an inflammatory remark praising what he described as ‘alpha males and alpha females’ for military service.
In his 2022 congressional bid, Cao expressed skepticism about U.S. aid to Ukraine, saying the funding borrowed to support the war risked depleting U.S. strategic reserves. His résumé includes graduation from Thomas Jefferson High School for Science and Technology, the U.S. Naval Academy, service as a special operations officer with SEAL teams and other units in Iraq, Afghanistan and Somalia, and retirement at the rank of captain. He has a master’s degree in physics and has held fellowships at MIT and Harvard.
As undersecretary, Cao advocated for allowing service members who refused a Biden-era COVID-19 vaccine mandate to return to duty.
The abrupt departure of Phelan adds to uncertainty at the Pentagon as senior civilian and military billets continue to turn over, and it places Cao temporarily in charge of the Navy at a time of high operational demand and ongoing congressional scrutiny of force posture and budgets.