In the biggest prisoner swap with Moscow since the Cold War, the Biden administration on Thursday secured the liberation of 16 American and German nationals held prisoner in Russia and Belarus in exchange for the release of eight Russians. 

The top of Russian President Vladimir Putin’s list was hit man Vadim Krasikov, who used the cover name Vadim Sokolov and was convicted by a German court for the 2019 assassination of a former Chechen commander near Berlin’s parliamentary building. 

"Krasikov is a high-ranking colonel in the elite Spetsnaz unit of the FSB," Rebekah Koffler, former DIA intelligence officer and author of "Putin’s Playbook," told Fox News Digital in reference to Russia’s intelligence agency the Federal Security Service (FSB).

Vadim Krasikov (Reuters)

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"Krasikov is a very high-value asset who will be debriefed by the Russian security services on the operation, how he got apprehended, what he learned during the interrogations in Germany, and everything the Russians are interested in," she explained. "These debriefings will help the Russians to make improvements in their operational tradecraft for Russian intelligence."

Koffler also said it is likely the Putin operative will be used to train "would-be assassins for future operations, making them even more lethal and difficult to detect and apprehend. … Putin also wants to show to would-be recruits that he would personally get involved in getting his people out if they are caught. It’s a huge recruitment incentive."

FSB assassin Vadim Krasikov, sentenced to life in 2021, was exchanged on August 1st, 2024 as part of a major prisoner swap; seen here greeted by President Vladimir Putin on his arrival to Russia. (East2West)

Reuters reported that Krasikov, who was born in Kazakhstan in 1965 while it was still part of the Soviet Union, became a specialist assassin while working for the FSB, according to Bellingcat reporting. 

Despite multiple witnesses to his assassination of the Chechen commander, which was carried out in daylight, Krasikov pleaded innocent and maintained he was a St. Petersburg construction engineer visiting Berlin as a tourist who went by the name Sokolov.

Though he was never directly confirmed as an agent by Moscow, Putin indirectly spoke of Krasikov in 2023 when he expressed a desire to secure the release of someone who "eliminated a bandit in one of the European capitals."

Vladimir Putin greets FSB assassin Vadim Krasikov, as part of a major prisoner swap with the U.S. and other Western countries. (East2West)

Ukraine's Security Service helped investigators identify the Russian FSB agent after obtaining footage of the man during his second wedding held in Kharkiv in 2010. 

According to Reuters reporting, Krasikov never recognized the court during his trial and frequently refused to listen to the translation of the proceedings provided to him.

Reports have suggested the prisoner swap would not have taken place without the release of Krasikov, placing an enormous weight on the shoulders of German Chancellor Olaf Scholz.

"Our obligation to protect German nationals and our solidarity with the USA were important motivations," the German government said Thursday, according to a Reuters report.

President Biden also championed Germany’s efforts in the prisoner swap and said, "I particularly owe a great sense of gratitude to the chancellor."

Evan Gershkovich, Alsu Kurmasheva and Paul Whelan are shown on a plane after being released from Russian prison in a historic prisoner swap on Aug. 1, 2024. (U.S. Government)

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"The demands they were making to me required me to get some significant concessions from Germany," he said. "But everybody stepped up. Poland stepped up, Slovenia stepped up, Turkey stepped up."

"It matters to have relationships. It really does," Biden added.

Among the prisoners set to return to the U.S. are Wall Street Journal reporter Evan Gershkovich, former Marine Paul Whelan and Russian-American journalist Alsu Kurmasheva, along with legal permanent resident Vladimir Kara-Murza.

The other 12 prisoners to be brought back from Russia are all German nationals who were held as political prisoners. 

The massive swap involved at least seven countries over a number of months to pull all the Russian prisoners requested by Moscow from the U.S., Germany, Norway, Slovenia and Poland, the White House said on Thursday.

President Biden speaks about the release of Paul Whelan, Evan Gershkovich, Alsu Kurmasheva and Vladimir Kara-Murza, who were detained in Russia, during a brief event where some of their relatives were in attendance at the White House on Aug. 1, 2024. (Reuters/Nathan Howard)

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"There has never been, so far as we know, been an exchange involving so many countries, so many close U.S. partners and allies working together," National Security Advisor Jake Sullivan told reporters.  "It's the culmination of many rounds of complex, painstaking negotiations over many, many months."

Biden called the historic swap a "a feat of diplomacy."

"Some of these women and men have been unjustly held for years. All have endured unimaginable suffering and uncertainty. Today, their agony is over," he said in a statement.

Reuters contributed to this report.