The Pentagon announced the immediate resignation of US Navy Secretary John Phelan on Wednesday, marking a sudden leadership change amid rising military tensions in the Gulf region. Pentagon spokesperson Sean Parnell stated that Phelan was departing without providing reasons for his exit. This decision comes just a day after Phelan addressed a significant gathering at the Navy’s annual conference in Washington, D.C., where he discussed his priorities. Phelan's resignation follows a series of high-level removals within the US defense establishment, including the recent dismissal of Army chief Randy George. The changes have occurred without detailed explanations, raising concerns within military circles. Phelan, who was nominated by former President Donald Trump in late 2024, had no prior military service and was known for his substantial donations to Trump's campaign. He will be succeeded by Navy Undersecretary Hung Cao, a decorated veteran with 25 years of service and previous Senate candidacy in Virginia. The Pentagon has not elaborated on the reasons for Phelan’s departure, and his office was unavailable for comment.