President Trump on Wednesday revoked the security clearance of John O. Brennan, the former C.I.A. director under President Barack Obama, citing what he called Mr. Brennan’s “erratic” behavior.
The White House had threatened last month to strip Mr. Brennan and two other Obama administration officials — Susan E. Rice, the former national security adviser; and James R. Clapper Jr., the former director of national intelligence — of their security clearances. At the time, Ms. Sanders said that Mr. Trump was considering doing it because “they politicized, and in some cases monetized, their public service and security clearances.”
Mr. Trump has questioned the loyalties of national security and law enforcement officials and dismissed some of their findings — particularly the conclusion that Moscow intervened in the 2016 election — as attacks against him.
Mr. Brennan has become a frequent critic of Mr. Trump since the 2016 presidential election, often taking to Twitter to question the president’s ability to serve in the Oval Office.
In a tweet this week, Mr. Brennan criticized Mr. Trump for the language that the president used to attack Omarosa Manigault Newman, his former top aide, who he called a “dog.”
Mr. Brennan wrote, “It’s astounding how often you fail to live up to minimum standards of decency, civility, & probity. Seems like you will never understand what it means to be president, nor what it takes to be a good, decent, & honest person. So disheartening, so dangerous for our Nation.”
Mr. Trump’s decision to revoke Mr. Brennan’s security clearance was announced by Sarah Huckabee Sanders, the White House press secretary. Ms. Sanders said the president is reviewing the security clearances of other former Democratic officials who have been critics of the president.
Former high-ranking officials in defense, intelligence, diplomacy and law enforcement usually maintain their clearances to advise those still in government. A clearance also serves a more personally profitable function: helping departing officials get jobs at security contractors or similar firms.
Revoking their access to classified information could weaken their ability to work as consultants, lobbyists and advisers in Washington. Nearly 4.1 million people have security clearances, according to the most recent report by the Office of the Director of National Intelligence, including 1.3 million with top secret clearances.
The announcement of the change in Mr. Brennan’s security clearance came as the White House has been mired in a public relations crisis created by the allegations from Ms. Manigault Newman, who has said the president suffers from mental incapacitation and has used racial slurs.
Ms. Sanders read a statement from Mr. Trump that indicated that the reason for the revocation of Mr. Brennan’s security clearance was because he is among a group of former officials who have “transitioned into highly partisan” people.
She also said Mr. Brennan had provided inaccurate testimony before Congress. She did not say whether the administration has evidence that Mr. Brennan had misused any classified information that he has had access to as a former intelligence official.
She denied that the officials, including Mr. Brennan, were chosen because they are all critics of the president.
Michael D. Shear / New York Times