According to an advisor working closely with President-elect Donald Trump on his transition process, Trump has offered retired Lt. Gen Michael Flynn the influential position of national security adviser. (Video: Reuters / Photo: AP)

According to an advisor working closely with President-elect Donald Trump on his transition process, Trump has offered retired Lt. Gen Michael Flynn the influential position of national security adviser. (Video: Reuters / Photo: AP)

The most influential national security job in the still-forming Trump administration will likely go to a retired three-star general who helped dismantle insurgent networks in Afghanistan and Iraq but then surprised — and sometimes dismayed — colleagues by joining the political insurgency led by Donald Trump.

As national security adviser to Trump, retired Lt. Gen. Michael T. Flynn would be responsible for helping a president with no national security experience navigate complicated global issues including the unfinished campaign against the Islamic State, the expansionist agenda of China and rising aggression from Russia. Flynn’s selection for the post was confirmed Thursday night by a person close to the Trump transition team who spoke on the condition of anonymity to discuss internal conversations.

[How Flynn went from intel officer to leading ‘lock her up’ chants]

As a decorated military intelligence officer and former head of the Defense Intelligence Agency, Flynn has deep experience to draw upon as he serves as Trump’s principal point of contact with the State Department, the Pentagon and a collection of U.S. intelligence agencies that have surged in power and influence since the Sept. 11, 2001, attacks.

“This is a guy who has the president’s trust, has credentials with the military, credentials with the intelligence community and credibility with Congress,” said Rep. Devin Nunes (R-Ca.), the chairman of the House Intelligence Committee and a member of the Trump transition team. “He’s a very serious person. He takes his job very seriously.”

1 of 74 Full Screen Autoplay Close Skip Ad × Here’s what president-elect Donald Trump has been doing after the election View Photos He has been holding interviews and meeting with Congress and the president as he prepares to transition into the White House. Caption He has been holding interviews and meetings as he prepares to enter the White House. Jan. 19, 2017 President-elect Donald Trump and his wife, Melania, visit the Lincoln Memorial before the “Make America Great Again” concert. Jabin Botsford/The Washington Post Buy Photo Wait 1 second to continue.

But Flynn has also shown an erratic streak since leaving government that is likely to make his elevation disconcerting even to the flag officers and senior intelligence officials who once considered him a peer.

Flynn stunned former colleagues when he traveled to Moscow last year to appear alongside Russian President Vladi­mir Putin at a lavish gala for the Kremlin-run propaganda channel RT, a trip Flynn admitted he was paid to make and defended by saying he saw no distinction between RT and U.S. news channels such as CNN.

Flynn said he used the trip to press Putin’s government to behave more responsibly in international affairs. Former U.S. officials said Flynn, seen dining next to Putin in photos published by Russian propaganda outlets, was used as a prop by the autocratic leader.

[Transcript: Michael T. Flynn on his dinner with Putin and supporting Trump]

Flynn was forced out of his job as director of the Defense Intelligence Agency in 2014 over concerns about his leadership style. After the ouster, he frequently lashed out in public against President Obama and blamed his removal on the administration’s discomfort with his hard-line views on radical Islam.

Spurning the decorum traditionally expected of retired U.S. flag officers, Flynn became a fervent campaigner for Trump and was given a high-profile role speaking before the GOP convention, an appearance in which he led the crowd in “lock her up” chants against Democratic nominee Hillary Clinton.

Flynn’s behavior drew the ire of former colleagues and superiors, including retired Gen. Stanley A. McChrystal, who made Flynn his top intelligence officer during critical stretches of the wars in Afghanistan and Iraq.

Retired Lt. Gen. Michael T. Flynn called for Hillary Clinton to drop out of the presidential race during the Republican National Convention in Cleveland. (Republican National Convention)

McChrystal and retired Adm. Michael Mullen, former chairman of the Joint Chiefs of Staff, contacted Flynn and urged him to show more restraint, with Mullen warning that Flynn’s behavior could jeopardize White House trust in the military.

Flynn dismissed those concerns in an interview with The Washington Post earlier this year, saying efforts to quiet him impinged on his free speech rights. “When someone says, ‘You’re a general, so you have to shut up,’ ” he said, “I say, ‘Do I have to stop being an American?’ ”

Flynn continued to campaign for Trump and has said he has admired the mogul since their initial meeting. “I was very impressed,” Flynn said in the interview with The Post. “Very serious guy. Good listener. Asked really good questions . . . I found him to be very attuned to what was going on around the world.”

Civil rights groups denounced the Flynn selection, saying he has refused to reject Trump’s repeated statements supporting the use of waterboarding and other brutal interrogation measures on terrorism suspects. Trump has also advocated killing or capturing innocent relatives of terrorism suspects.

Asked about such proposals, Flynn said in an interview with Al Jazeera this year that he is a “believer in leaving as many options on the table right up until the last possible minute.”

“Michael Flynn has exhibited basic contempt for international law, including the Geneva Conventions and laws prohibiting torture,” said John Sifton, deputy Washington director of Human Rights Watch. “By offering the post to Flynn, President-elect Trump will be cementing a dark return to the illegalities of the Bush administration and further undermining the foundation of the international human rights system.”

A longtime Democrat and native of Rhode Island who grew up in a military family, Flynn has articulated an increasingly dark vision of the direction of the United States, saying that it has fallen into a struggle between “centrist nationalists” and “socialists.”

He has also warned that the United States is failing to adequately address the threat posed by what he calls a “diseased component” of Islam. “There’s something going on in the Muslim world,” he said. “Why do we have heightened security at our airports? It’s not because the Catholic Church is falling apart.”

That view, and his willingness to voice it publicly, put him in close alignment with Trump, who has called for Muslims in the United States to be registered, subjected to loyalty tests and in some cases deported.

In February, Flynn tweeted a link to a YouTube video with the message: “Fear of Muslims is RATIONAL: Please forward a link to this video so that people may learn the BASICS of Islam.”

As national security adviser, Flynn would be a White House insider in a unique position to influence Trump on almost all aspects of foreign policy. Trump has shown scant respect for the intelligence and institutions that shaped Flynn, dismissing an intelligence community assessment that Russia was interfering in the presidential election as “public relations.”

Trump has also said he probably knows more than American generals about how to succeed in conflict zones such as Syria, encouraged Russia to hack Clinton’s email accounts and called for the CIA to resume its harsh interrogation methods.

Flynn publicly opposed such ideas before his association with Trump, and it is not clear whether he would help the president-elect advance an agenda built around such positions and policies.

Flynn most recently raised eyebrows in Washington with the publication of an opinion article in which he called for wholesale changes in U.S. policy toward Turkey and the extradition of exiled cleric Fethullah Gulen, who resides in Pennsylvania and has been accused by the Turkish government of fomenting a coup attempt earlier this year.

Gulen’s “vast global network has all the right markings to fit the description of a dangerous sleeper terror network,” Flynn wrote in the piece, which was published in the Hill. Officials with ties to the Trump transition team said that Flynn did not clear that article with the campaign before it was published or disclose that his consulting firm had been hired for lobbying work by a group with ties to the Turkish government.

Read more: