Donald Trump’s nominee to lead the Cybersecurity and Infrastructure Security Agency (CISA), Sean Plankey, informed Homeland Security Secretary Markwayne Mullin and the White House that he is withdrawing his nomination after a 13-month stall, during which the well-regarded cybersecurity veteran faced mounting resistance.

“After thirteen months since my initial nomination, it has become clear the Senate will not confirm me,” he wrote in a letter sent to the White House, according to Politico.

Plankey was nominated by Trump last March but failed to be confirmed by the end of 2025. He was renominated in January, only to face resistance to his confirmation. While he waited for his CISA confirmation, he worked for then-DHS Secretary Kristi Noem on Coast Guard issues, retiring from the Coast Guard last month.

The administration’s failure to confirm Plankey comes amid great turmoil at the nation’s cybersecurity agency, which has suffered severe staff reductions and budget cuts since the start of Trump’s current administration, capped by the sudden departure of CISA’s acting director, Madhu Gottumukkala, in February, who was moved into a position at DHS following revelations of embarrassing security missteps he made during his short tenure.

Policy experts say this turmoil is not simply bureaucratic drift — it weakens US cybersecurity at a dangerous moment, inviting foreign adversaries to exploit the aimlessness of an agency that is crucial to national security. “It’s hard for an agency to go this long without confirmed leadership,” Michael Daniel, president and CEO of the Cyber Threat Alliance (CTA), told CSO. “That’s not a good place for the country to be.”

Problems on the Senate side

Although neither Plankey nor the White House has clearly stated why his nomination stalled, a series of poorly sourced allegations and reported behind-the-scenes maneuvering over the past few months indicate that adversaries to Plankey’s confirmation were working to derail his leadership of the agency.

On the surface, two Senators vowed to stop Plankey’s CISA confirmation. Sen. Rick Scott (R-FL) blocked Plankey’s nomination due to a Coast Guard issue. At the same time, Sen. Ron Wyden (D-OR) held up Plankey’s nomination to force CISA to release an unclassified report on telephone network security.

A knowledgeable source told CSO they heard on the “backchannel” that someone on the Senate side called on US Representative Hillary Scholten (D-MI) to send a March 24 letter to DHS Inspector General Joseph Cuffari to investigate Plankey’s connection to a government contracting firm, alleging that he failed to cut his financial ties with the firm before his CISA nomination.

However, the CEO of that firm told CSO he was blindsided by Scholten’s letter and that Plankey had forfeited all financial interest in the company prior to the announcement of his CISA nomination. The CEO told CSO he sent a letter to the Coast Guard detailing the facts after Scholten — who he said never contacted his company — sent her letter to DHS.

CSO contacted Scholten’s office multiple times seeking comment, but received no response. CSO also received no response to the questions surrounding this letter from either DHS or CISA. CSO made efforts to reach Plankey for comment, but yielded no response.

Questions over who wanted Plankey blocked

On March 3, Ana Visneski, a former head of global disaster response at Amazon Web Services and former chief of digital media for the US Coast Guard, posted on Bluesky that she was “hearing from multiple sources” that Plankey “has been fired and escorted out of Coast Guard HQ by security,” a post that was picked up by at least one influential military analyst. Visneski did not respond to CSO’s request for comment.

Following Visneski’s social media post, CBS News published a report repeating the allegation, saying that Plankey was abruptly escorted out of the US Coast Guard headquarters and had his access badge removed. CBS News also reported that sources said Plankey’s renomination was made in error, which the White House denied.

The CBS report also highlights longstanding tensions between Plankey and Madhu Gottumukkala over cybersecurity contracts. Gottumukkala had been former DHS Secretary Kristi Noem’s CIO in North Dakota, and Plankey, by all accounts, had an excellent relationship with Noem while at DHS.

Two sources told CSO that it was highly unlikely that Plankey was fired because he received a Coast Guard award days after he was supposedly escorted out of the building, and, moreover, he was still the CISA nominee at that point, an unlikely status if he had indeed been fired.

A weak agency in the middle of a hot war

Whatever harm may have been done to Plankey, it is certain that the lack of leadership at CISA risks damage to the nation’s security, particularly in the middle of the Iran war.

“Cybersecurity is not just a law enforcement or an economic issue,” CTA’s Daniel said. “It’s both of those things, but it is also a national security issue. And we are in a position now where we have started a hot war, a kinetic war.”

He added, “One of the tools that Iran has at its disposal is its cyber capabilities, and it would be foolish of anyone to think that Iran would not at least consider targeting US critical infrastructure because of that ongoing conflict. You have left your nation’s cyber defense agency, which is responsible for working with critical infrastructure across the whole country, leaderless when you’re in an active hot conflict. So that seems like a problem to me.”

Just how long CISA will be leaderless is unclear. One thing that is clear is that Plankey will support whoever does become the next CISA leader.

“While I humbly request the removal of my nomination, I wholeheartedly support President Trump’s upcoming nomination for CISA and look forward to the continued success of the United States of America,” Plankey told the White House.

In the end, the story may be less about Sean Plankey than about what happens when Washington treats cybersecurity leadership as expendable. Leaving the nation’s primary cyber defense agency weakened, underfunded, and without confirmed leadership is not simply a personnel problem — it is a national security risk.