Last spring, it seemed Tucker Carlson might have reached the end of his fiery path through American media and politics.

Fox News canceled his top-rated show, depriving Mr. Carlson of his nightly platform in prime time. But it kept him under a contract, worth more than $15 million a year, that prohibited him from taking a job with a rival.

Under the old rules of the legacy media, Mr. Carlson would have been off the air and out of sight through the end of the 2024 election, when his contract runs out. But Mr. Carlson is no typical television star. And what was once normal in his industry is increasingly archaic, shattered by the new rules — or lack thereof — of the fractured online media world.

In landing an exclusive interview with President Vladimir V. Putin of Russia — released on Thursday on the social network X and Mr. Carlson’s own streaming site, Tucker Carlson Network — the host has returned with a vengeance to the center of American politics.

The two-hour interview gave him a bullhorn to an American audience just as many congressional Republicans worked to block a vital lifeline of American military aide to Ukraine.

It also accomplished Mr. Carlson’s goal of recapturing the spotlight. For the first time since his defenestration from Fox, his name was once again on the lips of major national and international figures, the kind of notoriety on which Mr. Carlson has long thrived.

Hillary Clinton, in an interview this week with Alex Wagner of MSNBC, called him “a useful idiot” and Mr. Putin’s “puppy dog.”

Mr. Carlson gave Mr. Putin room for uninterrupted disquisitions on longstanding and decidedly one-sided grievances about Ukraine’s origins and independence movements. But Mr. Carlson occasionally pressed, to Mr. Putin’s visible annoyance, including about why Russia was imprisoning Evan Gershkovich, the Wall Street Journal reporter, challenging Mr. Putin’s assertion that Mr. Gershkovich was a spy.

Whether the interview lifts Mr. Carlson’s standing in the long term remains to be seen.

The interview with Mr. Putin will serve as an advertisement of sorts for his streaming site, which he founded in December and costs subscribers $9 a month. Tucker Carlson Network is an attempt to replicate the business model of other conservative personalities like Megyn Kelly and Ben Shapiro, who have built stand-alone digital platforms outside of traditional media. Mr. Carlson is working with Red Seat Ventures, a firm that counts Ms. Kelly, Bari Weiss and Nancy Grace among its clients, to handle advertising sales on the new platform.

Until now, however, Mr. Carlson’s self-produced interviews on X — which lack the slick production values he once enjoyed on cable TV — have not had the same obvious influence on the national debate that he wielded on Fox News.

His waning power seemed to be at least part of the reason that Fox had not done more to stop his new endeavor even though Fox said it violated the terms of his contract. (Mr. Carlson’s lawyers have argued that Fox breached his contract originally, and that his online show falls within his free speech rights.)

If Fox pursued a case against Mr. Carlson, that could give him an opening to claim his former “corporate media” overlords, as he likes to call them, were trying to censor him. It’s just the sort of argument that plays to Mr. Carlson’s fan base, which resembles a political movement in its own right, giving Mr. Carlson leverage afforded to few other television stars.

It was that leverage that made Mr. Carlson such a boon to Mr. Trump — and Mr. Putin — during his time at Fox News.

Mr. Carlson was the network’s most prominent promoter of pro-Russian arguments, including his assertion that President Volodymyr Zelensky of Ukraine is a dictator being used by the West to undermine Russia.

But his propagandistic style also took him to the limits of cable television.

His involvement in Dominion Voting Systems’ defamation lawsuit against Fox that settled for $787 million — and the pretrial discovery of a text from Mr. Carlson conveying inflammatory views about violence and race — influenced his corporate bosses, Lachlan and Rupert Murdoch, in their decision to cut his show.

Mr. Musk stepped in quickly to make Mr. Carlson the first host of a long-form video show on X.

Mr. Musk completed his purchase of X in late 2022, vowing to make it an absolute “free speech” zone, a promise he reiterated when he was on Mr. Carlson’s show just before it was canceled last April. “Free speech is the bedrock of a functioning democracy,” Mr. Musk explained to Mr. Carlson, who hailed him for “restoring free speech to the internet.”

At X, Mr. Musk could offer Mr. Carlson a freer level of speech, in part because internet platforms like his have more legal protections from defamation suits like the one Dominion brought against Fox. And Mr. Musk has shown no concern about content that might alienate advertisers. (X has pitched packages that cost $300,000 for ads on four of Mr. Carlson’s videos, and up to $1.5 million for ads on 48 videos, according to internal documents obtained by The New York Times.)

Mr. Carlson pushed and ultimately broke the limits of what the Murdochs could allow on their network. He has not come close to that boundary for Mr. Musk, who reinstated thousands of previously banished accounts that promoted health and election misinformation, corresponding with a rise in racist and antisemitic messages on the social network. On Thursday, Mr. Musk, the most followed user on the platform, shared the interview with Mr. Putin with his followers.

Mr. Carlson’s show has featured well-known Americans, such as Alex Jones, who have run afoul of the content moderation policies on many social media platforms — including Twitter, as X was known before Mr. Musk bought it and eliminated most of those policies.

Other guests have included the independent presidential candidate Robert F. Kennedy, Jr., and Prime Minister Viktor Orbán of Hungary, each of whom have received a supportive reception from Mr. Musk on X.

That shared outlook has at times extended to Ukraine and Russia. Mr. Musk has angered Ukrainians by suggesting they negotiate for peace, which they equate with allowing Mr. Putin to keep Ukrainian territory he took through bloody and illegal force.

And, though Mr. Musk has granted Ukraine use of his Starlink satellite system for battlefield communications, he has acknowledged blocking its use for a planned attack against Russia in the Black Sea last year. Mr. Putin has, in turn, praised Mr. Musk as a “talented businessman.”

Mr. Putin’s spokesman, Dmitri Peskov, had similarly warm words for Mr. Carlson this week, saying Mr. Putin granted him an interview — which Mr. Carlson has been seeking since his Fox days — because Mr. Carlson “contrasts the position of the traditional, Anglo-Saxon media.”

Mr. Peskov debunked Mr. Carlson’s false suggestion that he was the first Western media figure to interview Mr. Putin since his full scale invasion of Ukraine two years ago because journalists hadn’t bothered to ask. Numerous Western outlets have made those requests, including The Times.

But Mr. Peskov agreed with Mr. Carlson that traditional media “cannot boast of attempts to even look impartial.”

Russia has defined impartiality as hewing to its official line, deviation from which risks the decidedly censorious penalty of jail time. That goes against traditional journalistic standards — standards that Mr. Carlson does not have to concern himself with at X.

The interview seems certain to attract a big audience. The test will be whether it results in more subscriptions and interest in his show going forward — and if not, how Mr. Carlson will try to outdo himself for his next splash.

Kate Conger contributed reporting.