Michael Flynn's downfall was as swift as his rise to become Donald Trump's top national security aide was slow and steady.
After three decades climbing the ranks of US military intelligence, it took just 10 months from being sworn in as the president's national security advisor for a disgraced Flynn to plead guilty to charges of lying to the FBI.
A pivotal player in Trump's shock election campaign, Flynn's admission on Friday that he lied about contacts with Russia, hurtled him into the center of a scandal that could imperil the presidency itself.
Flynn's stride into Washington's district courthouse instantly entered the annals of American political history -- right alongside Watergate mugshots and grainy images of JFK's fateful open-top ride in Dallas.
In pleading guilty, the 58 year-old also pledged to cooperate with the deepening FBI probe into possible collusion between Trump's campaign and a Russian effort to tilt the 2016 election in his favor.
A wiry, energetic figure with sharp facial features, the retired three-star general was one of the few high-profile military figures willing to embrace Trump during the Republican's maverick election campaign.
Flynn's hardline stance on militant Islam and his penchant for engaging Russia had seen him forced out as the head of Barack Obama's Defense Intelligence Agency.
But those very same views drew him into Trump's orbit.
Such was their personal bond that he was even on the shortlist for vice presidential candidate.
At the Republican convention that nominated Trump for president, Flynn delivered a fiery attack on Democrat Hillary Clinton, even leading the crowd in chants of "Lock her up!"
But his own fate was sealed when he discussed US sanctions with Russia's ambassador weeks before Trump was sworn in as president, just as then-president Obama was ordering new actions against Moscow over its alleged interference in the US election.
Barely a month into his job as White House national security advisor, Flynn was forced to resign in February due to public concerns over his contacts with the Russian envoy.
It was not the first time Russia had become a problem for the retired army lieutenant general.
His paid appearance at a 2015 dinner in Russia sitting next to President Vladimir Putin especially raised eyebrows, as did his accommodating statements toward Moscow that suggested a readiness to accept Russia's seizure of Crimea and its support for Syrian leader Bashar al-Assad.
"We beat Hitler because of our relationship with the Russians, so anybody that looks on it as anything but a relationship that's required for mutual supporting interests, including ISIS, ... that's really where I'm at with Russia," he told the Washington Post in August 2016.
The main threat facing America, in Flynn's view, was militant Islam.
"We have a problem with radical Islamism and I actually think that we could work together with them against this enemy. They have a worse problem than we do," he told the Post.
The son of a Rhode Island banker, Flynn had a professional army career mainly in intelligence units. In the 2000s he served in Iraq and then Afghanistan, where he became director of intelligence for coalition forces.
After leaving the Defense Intelligence Agency, Flynn repeatedly criticized the Obama administration as inadequately focused on the Islamist threat.
In his book, Flynn argued that Muslim countries must be forced to stamp out radical Islamic beliefs, which he said were "metastasizing."
"We're in a global war, facing an enemy alliance that runs from Pyongyang, North Korea, to Havana, Cuba, and Caracas, Venezuela," he wrote in the New York Post. "Along the way, the alliance picks up radical Muslim countries and organizations such as Iran, Al-Qaeda, the Taliban and Islamic State."
Like Trump, Flynn criticized US allies in NATO for not putting enough of their own effort and funding into the western defense treaty.
National security community critics had warned his one-dimensional views could upset well-established relationships that benefit the United States.
They questioned Flynn's willingness to take money from Russian government-backed groups, and his support for Turkish President Recep Tayyip Erdogan's harsh crackdown on dissent.
His brief, but pivotal, relationship with Trump now lies in tatters.
Having reached a plea deal with the FBI, he has now flipped against his old boss, promising to tell investigators details of which "very senior member" of the presidential transition team instructed him to approach Russia.
In response, the White House threw Flynn under the bus.
Describing him as "a former Obama administration official" White House lawyer Ty Cobb said he was only part of the Trump administration for "25 days."
They may turn out to be the most consequential 25 days of his long career.