When our Ira Stoll reviewed Natan Sharansky’s latest book, “Defending Identity,” for these pages last week, he concluded by writing, “Mr. Sharansky’s last book, ‘The Case for Democracy,’ was famously endorsed by Mr. Bush, who gave Mr. Sharansky the Medal of Freedom. If the next American president reads this latest book by Mr. Sharansky on the interplay between identity, democracy, and freedom, it could be more important than any CIA or State Department briefing in understanding the foreign policy horizon.”

It turns out the chances that the next president will read Mr. Sharansky’s book are higher than they were last week. For in Washington this week, the former prisoner of conscience in the Soviet Union presented a copy of the book to Senator McCain, who promised to read it in one night. As Mr. Sharansky recounted the meeting yesterday during a visit to The New York Sun, Mr. McCain began by remarking that Mr. Sharansky’s nine years in the Soviet Gulag had been different from Mr. McCain’s five and a half years in North Vietnam, because Mr. McCain knew that the North Vietnamese would, for propaganda reasons, forbear killing him, while Mr. Sharansky had to be prepared to die.

Mr. Sharansky replied that the two men had some similarities in their prison experiences, both having refused offers by their captors of premature release. “Many people to this day don’t understand why I refused,” Mr. Sharansky said. Mr. McCain, though, “immediately understood,” according to Mr. Sharansky, who wryly suggested that a campaign slogan used by his party of Russian émigré politicians in Israeli elections might be adopted by Mr. McCain: “We’re a different type of party. We go to prison first.”

Mr. McCain’s detractors have long suggested that the experience scarred him mentally as well as physically. But in our view, as the Sharansky campaign slogan suggests, experience in a totalitarian prison can toughen one’s mind and deepen one’s commitment to freedom. It’s not the only way to achieve such gains; President Bush never spent time in the gulag, yet has developed an understanding of the stakes in the struggle for freedom; Senator Obama never was jailed by a dictatorship, yet he has developed high ideals, and it wouldn’t surprise us to see Mr. Obama take a strong foreign policy stance on democracy and human rights between now and the general election.

But actually sitting in a Soviet or a North Vietnamese or for that matter a British or Iranian or Iraqi prison — well, that is an experience that, if it does not break a person, can bring a firsthand appreciation of freedom and why it is worth fighting for. For those of us who are partisans in the global struggle for freedom — and we believe that the majority of Americans and of individuals around the world deep in their souls are — it is an encouraging thought about Mr. McCain. And as Prime Minister Olmert faces a corruption probe in Israel and Mr. Obama’s crony Tony Rezko is found guilty on 16 counts, “We go to prison first” is a slogan that could have its advantages.