It also projects the wrong image to America's enemies and allies, as a cascading series of leadership changes calls into question the stability of America's sea service.

“There is never a good time for a crisis in leadership, but having it in the middle of a pandemic is a particularly awful time,” said Ray Mabus, who served as Navy secretary under former President Barack Obama.

Lawmakers, national security experts and Navy veterans alike disavowed Modly’s extraordinary remarks to the crew of the aircraft carrier Theodore Roosevelt on Sunday. Modly had just fired Capt. Brett Crozier for blasting an email to Navy personnel asking for aid as the carrier was forced to dock in Guam, coronavirus running rampant through the ship's decks.

In a speech to the crew that was later leaked to the media, Modly called Crozier’s actions “naïve” and “stupid.” The decision to give the address, as well as the abrupt move to fire Crozier before uniformed Navy officials had completed an investigation into the incident, crossed a critical line, upsetting the delicate balance between civilian and military control of the service, former officials said.

“The final adjudication is with the chief of naval personnel,” said retired Vice Adm. John Miller, former commander of 5th Fleet, which oversees the Middle East. “Having Modly, who is senior to everyone in uniform in the Navy, be the relieving officer makes that whole review process more difficult.”

Others called for the speedy confirmation of a permanent replacement for the last Senate-confirmed Navy secretary, Richard Spencer. After Spencer was ousted in late November over his handling of Navy SEAL Chief Eddie Gallagher — President Donald Trump wanted the chief's SEAL insignia restored after granting the sailor clemency — Trump nominated Kenneth Braithwaite, the former ambassador to Norway, for the job. Yet his nomination has languished in the Senate for several weeks.

After a break-neck chain of events that began when Crozier's letter asking for help surfaced on March 31, followed by Modly's firing, his speech to the crew and Tuesday's departure, the Navy Department now finds itself under the temporary leadership of James McPherson, retired rear admiral who was confirmed to be the Army's No. 2 a mere 15 days ago.

“The Department of the Navy needs to have a Senate-confirmed Secretary of the Navy — now,” said Michael Mulroy, who served as deputy assistant secretary of defense for Middle East policy until December and now works for ABC News.

After meeting with Defense Secretary Mark Esper on Tuesday morning, Modly sent a letter to his boss saying it was time to go.

"He resigned on his own accord, putting the Navy and Sailors above self so that the USS Theodore Roosevelt, and the Navy as an institution, can move forward," Esper said in a statement.

Defense Secretary Mark Esper “did not care for” Modly’s comments on the carrier, said a second senior defense official. | Alex Brandon/AP Photo

In his resignation letter, a copy of which was obtained by POLITICO, Modly thanked Esper and Trump for their "confidence" in him.

"More than anything, I owe every member of the Navy and Marine Corps team a lifetime of gratitude for the opportunity to serve for them, and with them, once again," Modly wrote. "The men and women of the Department of the Navy deserve a continuity of civilian leadership befitting our great Republic, and the decisive naval force that secures our way of life."

Modly was more loquacious in a memo to the force, in which he acknowledged that he “lost situational awareness” during his address to the Roosevelt’s crew.

“You are justified in being angry with me about that,” Modly wrote in the memo. “There is no excuse, but perhaps a glimpse of understanding, and hopefully empathy.”

“I am deeply sorry for some of the words and for how they spread across the media landscape like a wildfire,” Modly continued.

Later in the four-page memo, Modly urged sailors not to “ be afraid” to bring up issues of concern to their immediate superiors, but noted that “there is a proper, courteous and respectful way to do this.”

Just hours earlier, on Monday night, Modly apologized to the crew and its former captain,

"I want to apologize to the Navy for my recent comments to the crew of the TR,” Modly said in a statement. “Let me be clear, I do not think Captain Brett Crozier is naïve nor stupid. I think, and always believed him to be the opposite.”

Yet the mea culpa wasn't enough. On Monday and continuing throughout the day Tuesday, Democratic lawmakers called on Modly to resign or be fired.

Mabus criticized Modly’s remarks, noting in an interview that “the notion that a civilian leader would go on a warship and say these things about a captain who was obviously beloved and who had done this for his crew just defies imagination.”

Mabus blamed Trump for cultivating an environment in which “the only people who seem to thrive are people who either emulate or suck up to him.” He accused the president of politicizing the military and interfering with the military’s regular justice system.

“The tone comes from the top,” he said.