Minutes after President Joe Biden announced that WNBA basketball star Brittney Griner had been released from a Russian prison, Sen. James Lankford, R-Okla., criticized the deal Biden made to win her freedom.

"Always good to see an American that’s unjustly detained that's coming home," Lankford said Dec. 8 on Newsmax. "The problem with this is the Biden administration swapped someone that was known as the 'merchant of death.'"

Lankford added: "Literally, what Biden just did was equated an international arms dealer" with "someone that was being held in Russia for a small marijuana charge." 

Lankford was talking about Russian arms dealer Viktor Bout, who was midway through a 25-year federal prison sentence for offering to sell arms to a Colombian rebel group. 

Griner had been detained since February, when Russian authorities found less than 1 gram of a concentrated cannabis vape oil in her luggage at a Moscow-area airport. In August, she was sentenced to nine years in prison.

Other Republicans also criticized the deal. House Minority Leader Kevin McCarthy of California said it is "a gift to Vladimir Putin, and it endangers American lives."

Here’s what we know about Bout and what the Biden administration has said about exchanging him for Griner. 

"Merchant of Death" is a 2007 book profiling Bout written by two journalists, former Washington Post reporter Douglas Farah and then-Los Angeles Times correspondent Stephen Braun. 

In a 2006 Foreign Policy article, Farah and Braun called Bout "the world's most notorious arms trafficker." Their story said he "made millions as the world's most efficient postman, able to deliver any kind of cargo — especially illicit weapons — anywhere in the world." 

Bout’s clients for arms included the Taliban, Libyan strongman Col. Moammar Gadhafi and the Revolutionary Armed Forces of Colombia, widely known as FARC, but he also did business with the United States, according to Farah and Braun. 

"Over the past several years, the U.S. Treasury Department has tried to put Bout out of business by freezing his assets and imposing other sanctions on him, his business associates and his companies," the article said. "But the Pentagon and its contractors in Iraq and Afghanistan have simultaneously paid him millions of dollars to fly hundreds of missions in support of post-war reconstruction in both countries."

Michael Braun, who was a U.S. Drug Enforcement Administration official overseeing the U.S. effort to capture Bout, warned in an August article that trading Bout would pose a "grave threat to the national security of the United States and its allies," and would "encourage Moscow and other rogue regimes to take Americans hostage."

At the time, CNN reported that the Biden administration was considering trading Bout for Griner and former U.S. Marine Paul Whelan.

Braun's article said Bout began dealing Soviet-made weapons in the 1990s and by 2003 became "the world’s preeminent arms trafficker, flooding weapons to U.S.-designated terrorist organizations" and other groups.

In 2008, the Royal Thai Police, working with the DEA, arrested Bout in Bangkok. DEA operatives posed as members of FARC, which the U.S. designated as a terrorist organization.

In 2012, a federal court sentenced Bout to 25 years in prison for conspiring to sell FARC hundreds of surface-to-air missiles and 20,000 AK-47s. "Bout understood that the weapons would be used to kill Americans in Colombia," the federal prosecutor said.

Bout, 55, was held at the medium-security federal penitentiary in Marion, Illinois, with a scheduled release in August 2029, according to the Federal Bureau of Prisons.

Biden did not mention Bout during his announcement of Griner's release. But he described negotiations with Russia as "painstaking" and "intense." 

When asked about national security concerns related to Bout’s release, White House press secretary Karine Jean-Pierre said Biden did not make the decision "lightly." 

"We will always stay vigilant about our national security," Jean-Pierre said at a press conference. "That was true yesterday. That is true today. And that will be true after Mr. Bout’s release." 

Griner is the second American returned from Russia this year after what the Biden administration characterized as wrongful detentions. Conservatives criticized Bout's release and said Whelan, a former U.S. Marine, was left behind.

Russia arrested Whelan on Dec. 28, 2018, on charges of espionage. He was sentenced to 16 years on July 15, 2020. 

"We've not forgotten about Paul Whelan, who has been unjustly detained by Russia for years," Biden said Dec. 8. "This was not a choice of which American to bring home." 

The Biden administration initially offered to exchange Bout for the release of both Griner and Wheelan, CNN reported. Russia did not agree to this trade, Biden said.  

"Sadly, (for) totally illegitimate reasons, Russia is treating Paul's case differently than Brittney’s," Biden told reporters. "While we have not yet succeeded in securing Paul, we are not giving up."

Secretary of State Antony Blinken said Russia continues to view Whelan's case as espionage. In this instance, the choice was "one or none," Blinken said.

Whelan's family backed Biden's decision to secure Griner's release, but they said it is a "public disappointment" for them and "a catastrophe for Paul." 

"The Biden administration made the right decision to bring Ms. Griner home and to make the deal that was possible, rather than waiting for one that wasn't going to happen," David Whelan, the former Marine's brother, said in a statement.