When I saw the faces of the Americans who were freed from Russian captivity, it not only brought tears to my eyes. It brought back memories of a prisoner exchange in which I played a significant role.

The Soviet dissent and refusenik Anatoly Shcharansky — now Natan Sharansky — was arrested in March 1977 on trumped-up charges of spying on America. His wife and mother asked me to help represent him on a pro bono basis.

For nearly a decade I worked with the great Canadian lawyer Irwin Cotler in order to secure Mr. Sharansky’s freedom. We knew that legal briefs alone would not do it. We also understood that if he were to be released for political or diplomatic reasons, the Soviets would need a legal justification.

So we prepared briefs and memoranda supporting his legal claims. We also decided to mount a public relations campaign to keep his face in the public view so that his captors could not simply make him disappear. We went to Congress, to international forums, to the press, to universities, and to anyone else who would listen. He was kept alive, but he still remained a hostage to the Cold War. 

Then a breakthrough occurred. The United States arrested an East German academic who was spying for the Soviet Union. I met with his lawyers, and we agreed to propose a swap. On Thanksgiving Day 1985, I went to Europe to meet with Wolfgang Vogel, the Soviet Union’s main spy trader whom you may remember from the movie “Bridge of Spies” with Tom Hanks.

At that meeting we agreed on the parameters of an exchange of prisoners that also involved South Africa. Nelson Mandela, to his credit, refused to participate in any exchange saying that he would remain in prison until his captors decided to release him. 

In early 1986, the terms of the prisoner exchange were finalized, and on February 11, 1986, Shcharansky walked over the Glienicke Bridge in Germany. When I met him, he embraced me and whispered a Hebrew prayer: “Baruch Matir Asurim,” which means blessed are those who free the imprisoned.

Since that time, Mr. Sharansky, who had changed his name from the Russian Anatoly to the Hebrew Natan, has become an important figure in Israel, serving both inside and outside of government. He also became a dear friend. For me, the case was the most satisfying in my long career.

I realized, though, that prisoner exchanges of the kind just announced by America are not without downsides. When the exchanges are between the United States and a tyrannical dictatorship like the Soviet Union or Russia, they are asymmetrical. 

The United States can only arrest people who are guilty of crimes. The Soviet Union can arrest anybody it can get its hands on, without regard to innocence or degrees of guilt (think the Brittney Griner case where she may have technically been guilty of the most minor offense). This means that Russia and other tyrannies can take hostages whenever they choose to and use them as bargaining chips. We cannot do that.  

Consider the recent trade. Russia freed journalists who were simply doing their job. Germany freed an assassin who had murdered a political dissident in cold blood. It was anything but a fair trade, but as National Security Advisor Jake Sullivan said, “They hold the keys.”

They not only hold the keys, they also decide whom the keys will be used to lock up. There is little that democracies can do to prevent tyrannies from creating bargaining chips that can then be used to free guilty murderers and other criminals. Yet as Sullivan also said, it is difficult to resist the moral and emotional desires of family members to see their innocent loved ones back home.

So the bad guys will continue to arrest innocent people and hold them as hostages and the good guys will continue to release bad guys in order to secure the freedom of good guys. It’s a sordid business but one that will never end as long as there are strong tyrannies willing and able to make the immoral rules that govern these sorts of prisoner exchanges.