An outspoken retired Navy admiral, who oversaw the Navy SEAL raid that killed al-Qaida leader Osama bin Laden, has issued a fiery open letter to President Donald Trump over his revoking the security clearance of former CIA Director John Brennan, comparing his tactics to those who led communist witch hunts in the 1950s.

William H. McRaven, commander of the U.S. Joint Special Operations Command from 2011 to 2014, published his letter on the Washington Post website today, requesting that Trump also revoke his security clearance, “so I can add my name to the list of men and women who have spoken up against your presidency.”

Brennan said today that Trump revoked his clearance because his presidential campaign colluded with the Russians to sway the 2016 election and now the president is desperate to end special counsel Robert Mueller’s investigation.

The former CIA director questioned whether Trump’s alleged collusion amounts to a “constituted criminally liable conspiracy.”

Trump said Wednesday he is reviewing the security clearances of several other former top intelligence and law enforcement officials, including former FBI Director James Comey and current senior Justice Department official Bruce Ohr.

All are critics of the president or are people whom Trump appears to believe are against him.

The revocation has been seen by many as an unprecedented act of retribution, in part for Brennan’s public criticisms of Trump. Top officials are commonly allowed to keep their clearances so they may continue to advise on security matters and hold certain jobs that require such clearances.

In his open letter, McRaven goes on to detail his disappointment in the current commander in chief:

“Like most Americans, I had hoped that when you became president, you would rise to the occasion and become the leader this great nation needs.

"A good leader tries to embody the best qualities of his or her organization. A good leader sets the example for others to follow. A good leader always puts the welfare of others before himself or herself.

"Your leadership, however, has shown little of these qualities. Through your actions, you have embarrassed us in the eyes of our children, humiliated us on the world stage and, worst of all, divided us as a nation.

"If you think for a moment that your McCarthy-era tactics will suppress the voices of criticism, you are sadly mistaken. The criticism will continue until you become the leader we prayed you would be.”

Assistant Secretary of Defense for Special Operations/Low-Intensity Conflict Michael D. Lumpkin, left, and Adm. William McRaven, then commander of Special Operations Command, testify March 11, 2014, at a Senate Armed Services subcommittee hearing in Washington. (Jim Watson/AFP via Getty Images)
Assistant Secretary of Defense for Special Operations/Low-Intensity Conflict Michael D. Lumpkin, left, and Adm. William McRaven, then commander of Special Operations Command, testify March 11, 2014, at a Senate Armed Services subcommittee hearing in Washington. (Jim Watson/AFP via Getty Images)

It’s not the first time he has criticized Trump publicly.

In a speech to journalism and mass communication majors at the University of Texas at Austin in February 2017, McRaven shared his concerns over statements made by Trump at the time about media.

“On Feb. 17 the president said, ‘the news media is the enemy of the American people,’” McRaven said. “This sentiment may be the greatest threat to democracy in my lifetime.”

He encouraged the students to challenge Trump’s sentiment and statement at every opportunity.

The retired admiral gained widespread fame during his 2014 commencement speech his alma mater the University of Texas at Austin in which he told the graduating students that, “If you want to change the world, start off by making your bed.”

The statement became a social media meme and led to a book McRaven authored, titled, “Make Your Bed: Little Things That Can Change Your Life…And Maybe The World.”

The Associated Press and the Washington Post contributed to this article.