While Russia has detained and officially charged Paul Whelan -- a dual U.S.-British citizen -- with espionage, questions have arisen over whether this is a real spy case or just another move in a decades-old Cold War game.
Whelan, a former Marine who his family says was in Moscow for a friend’s wedding, has been held since December 28 and was charged with spying on January 3.
But is the 48-year-old private-sector corporate security executive guilty of nothing more than being in the wrong place at the wrong time?
Some think so.
Whelan’s lawyer, Vladimir Zherebenkov, says his client may just be a pawn in a plan by Moscow to force a classic spy swap given that his arrest came weeks after Russian Maria Butina pleaded guilty in the United States to acting as an agent for the Kremlin.
A combo photo shows Paul Whelan and Maria Butina
The Kremlin has denied that Butina is a Russian agent and has organized a social-media campaign to secure her release.
In the past, Russia has sometimes arrested foreigners with the aim of trading prisoners with other countries.
"The thing is that in this category of cases, exchanges often happen," Zherebenkov told ABC News in a phone interview when asked about the next stages in the case.
"For an exchange to happen, there has to be a court. The court has to examine the case, to prove his guilt. The sentence must come into legal force. After that, the president can pardon him and an exchange can happen -- for Russians citizens that are in detention in America," he added, noting that Whelan intends to fight the charges and plead not guilty.
Either way, the case conjures up images of the two superpowers sending delegations to Berlin’s infamous Glienicke Bridge -- often called "The Bridge of Spies" -- to exchange people under the cloak of fog and nightfall.
Here are some of the notable spy and prisoner swaps between Moscow and the West over the past decades:
U.S. pilot Francis Gary Powers (right) attends an open session of the Military Board of the U.S.S.R. Supreme Court in Moscow on August 19, 1960.
February 10, 1962
One of the first major swaps saw Francis Gary Powers and Rudolf Abel exchanged in secrecy at the Glienicke Bridge between West Berlin and Potsdam after both were released from prison after being found guilty of spying.
The handover was the stuff of spy novels, with both men slowly walking across the bridge from their respective sides.
Rudolf Abel (center) is accompanied by U.S. marshals at Newark Airport on August 8, 1957.
October 11, 1963
A 24-year-old American student, Marvin William Makinen, who was arrested in Kyiv while traveling in 1961, and the Reverend Walter Ciszek, a Jesuit missionary arrested in the Soviet Union in 1941, are swapped for Ivan Egorov, a former United Nations worker, and his wife, Aleksandra, who had been captured in the United States and charged with espionage.
Greville Wynne is visited by his wife at the Supreme Court in Moscow on May 15, 1963.
April 22, 1964
British businessman Greville Wynne, jailed in 1963 on charges of spying for the United States and Britain, was exchanged on the Glienicke Bridge for Soviet intelligence officer Konon Molody, who had been imprisoned by the British in 1961 for masterminding the Portland Spy Ring.
Molody was known in the West as Gordon Arnold Lonsdale.
April 30, 1978
The United States, East Germany, and Mozambique execute a three-way swap of Miron Marcus, an Israeli citizen held in Mozambique; Robert Thompson, a former U.S. Air Force intelligence clerk convicted of passing states secrets on to the Soviet Union; and Alan Van Norman, an American whom East German authorities caught trying to smuggle a German doctor, and his wife and son to the West.
Soviet dissident Aleksandr Ginzburg
April 27, 1979
The Soviets release five dissidents -- including Aleksandr Ginzburg -- and fly them to New York City in exchange for Russians Valdik Enger and Rudolf Chernyayev.
The two were being held in the United States for espionage.
June 11, 1985
The Glienecke Bridge takes center stage again as a deal involving 29 people, including 23 Westerners and Poland’s most-famous spy, Marian Zacharski, is carried out.
Zacharski was serving a life sentence in the United States after being found guilty of passing along top-secret plans on radar and stealth aircraft technology that he obtained by duping an engineer at Hughes Aircraft.
February 11, 1986
The final act for the "Bridge of Spies" involved Soviet Jewish dissident Anatoly Shcharansky (better known as Natan Sharansky), who was imprisoned in the Soviet Union for spying on behalf of the United States, though it is commonly accepted that the charges were made up and that his real crime was criticizing the communist regime.
Soviet dissident Natan Sharansky in Jerusalem on December 3, 1986
A meeting between U.S. President Ronald Reagan and Soviet leader Mikhail Gorbachev in 1985 led to the deal to exchange Sharansky for Karel Koecher and his wife, Hana.
Both Czechoslovak nationals, Koecher pleaded guilty in 1984 to spying for the Soviet Union, while his wife was being held as a material witness in the case.
September 1986
American journalist Nicholas Daniloff, who reported on the Soviet Union, and Gennadiy Zakharov, a United Nations worker accused of spying for the Soviets, were released a day apart after three weeks of intense negotiations.
Soviet dissident Yuri Orlov was also released to the West as part of the deal.
The affair sparked a deep diplomatic crisis, with dozens of diplomats from both sides expelled in the weeks that followed the swap.
An airliner takes off after participating in a prisoner swap at Vienna International Airport on July 9, 2010.
July 9, 2010
The last major known swap involved 10 Russians released by the United States and four people released by Moscow in an exchange that took place in broad daylight on the tarmac of Vienna International Airport.
Two airplanes were parked beside each other to allow for the exchange, which included the Russian nuclear scientist Igor Sutyagin being allowed to emigrate to the West.
The Vienna swap also included Anna Chapman, a photogenic socialite who moved in Manhattan policymaking circles, who was returned to her native Russia.
Months after her release back to Russia, Chapman -- born Anna Kushchenko -- flaunted her freedom by posing for the Russian edition of Maxim magazine as a lingerie-wearing secret agent armed with a gun.
Anna Chapman back in Moscow in December 2010
Sergei Skripal was also part of the swap, with the Kremlin releasing the Russian military intelligence officer who was convicted in 2006 of spying for the U.K. Skripal ended up living in England, where he was allegedly poisoned by two Russian suspects in the city of Salisbury. Skripal almost died in the attack.
The United States released members of a spy ring the Justice Department called the "Illegals Program" who had just hours earlier pleaded guilty in New York to charges of "conspiracy to act as an unregistered agent of a foreign country."
These are the same charges to which Maria Butina has pleaded guilty.