One of the most treasured items on my office bookshelf is a dedication on a thin pamphlet, published in the Soviet Union in 1990, by one of the top authors of glasnost, political philosopher Igor Klyamkin. I became friends with him in the late 1980s. The dedication reads, in Russian, "To Leon Aron, who understands Ronald Reagan's role in our revolution."

What did Igor mean?

As the Soviet regime was disintegrating, Reagan was the most popular foreign leader in the U.S.S.R., followed by British Prime Minister Margaret Thatcher. Partly, of course, this was a tribute to Reagan's uncanny sense of realpolitik: He gave Moscow a cold shoulder when the Soviet regime was at its reactionary worst (post-Afghanistan, 1981-85) and his Strategic Defensive Initiative, derisively described as "Star Wars" by Reagan's detractors, was a direct challenge to a Soviet leadership that knew it could not technologically match it. SDI undoubtedly contributed to the "new political thinking" in Soviet foreign policy. Yet, Reagan sensed also that Mikhail Gorbachev was a genuine reformer and that a fundamental difference in the regime was underway. Reagan responded by traveling to the Soviet Union in May 1988.

But there was more to it. Far more. Like all great modern revolutions, the Russian revolution from 1987-91 was first and foremost a moral revolution, concerned with human dignity and liberty as its central component. Its mantra was tak dal'she zhit' nel'zya. "That's it. We cannot live like this any longer." This was repeated by the perestroika trio of Gorbachev, Eduard Shevardnadze and Alexander Yakovlev, as well as leading glasnost authors and millions of rank-and-file men and women. At its essence, this was about the rejection of the moral core of the "old regime"--and Reagan had a magnificent, unerring moral instinct. His clarity of vision and his rhetoric exposed the moral disfigurement of Soviet totalitarianism. This was a charge for which the regime had no answer.

We know of the whispered admiration within the Soviet Union for Reagan's "empire of evil" speech to the British Parliament in 1983. The dissident and "refusenik" Anatoly Shcharansky, who at the time was imprisoned in the gulag, recalled in his memoirs how the news was spread by Morse code knocks on the walls.

Similarly, Reagan's famous declaration at the Berlin Wall's Brandenburg Gate--"Mr. Gorbachev, tear down this wall!"--was a moral statement because it exposed the key sin of the Soviet regime that no amount of tanks could camouflage: the indignity of holding entire peoples in a cage.

Like all truly great political leaders, at critical moments Ronald Reagan was guided by and openly articulated a profoundly moral judgment of right and wrong, good and evil, liberty and slavery that resonated with tens of millions people in America and abroad. More than anything else, I think, it was this judgment that defined Reagan's "role" in Russia's latest revolution of which Igor wrote--and made it so effective.

Leon Aron is resident scholar and director of Russian studies at the AEI.