A Baltic Sea cruise to St. Petersburg, Russia's historic showplace, offers wonders galore, punctuated by breathtaking onboard views of dramatic Nordic coastlines. But I had a specific mission in mind for the seven-day voyage my wife, Eileen, and I took there in August - one that began with an excursion to Berlin.

As a U.S. Army cold warrior 45 years ago, briefly based in what was then West Germany, I aimed to make some sense of the vast changes in Europe since the Soviet Union's collapse.

Thanks to cultural insights gleaned in Germany's stately gem of a capital, and in Russia's glittering "second city," with its ornate czarist palaces filled with artistic treasures, we returned to the United States feeling far more knowledgeable about the country that Winston Churchill famously called "a riddle wrapped in a mystery inside an enigma."

Our two summer days in St. Petersburg reminded us how skewed our high school history lessons had been in the '60s. Our 862 fellow passengers hailed from more than 30 nations, but a majority were Americans, with many of those, like us, of retirement age. Thus, many had been teenagers back then. More than a few expressed surprise during the cruise to learn of the Soviets' decisive role in the defeat of the Nazis, for example, or the Germans' catastrophic 872-day Siege of Leningrad - as St. Petersburg was known during communist times - during which hundreds of thousands of Russians starved to death.

Whatever new impressions we got about Russian politics and history, though, were dwarfed by the impact of the masterpieces on display in the museums and palaces. They are one and the same in the case of the sprawling, pastel-tinted Hermitage, which stretches in a seemingly endless series of connected buildings along the Neva River embankment. Its core is the Winter Palace, with its high ceilings and lavishly gilded arched walls, where Catherine the Great began collecting matchless European works around 1762. Almost as astounding, though, is how a Soviet state built on hatred of czarist excesses had devoted itself to preserving the treasures those rulers had accumulated on the backs of peasants mired in poverty. (The simplest explanation we got: Even the communists prized the centuries-old cultural heritage of Mother Russia.)

The trip began to take shape early in the year. To celebrate Eileen's impending retirement, we booked a cabin on the Symphony, a 960-passenger ship operated by Crystal Cruise Lines. Our first cruise, through the Panama Canal, had been on Crystal seven years before, near my own semiretirement. That voyage had taught us that a premium price - $3,895 for this cruise, with extras reflecting choice of room and excursions - can come with such important but hard-to-value features as top onboard lecturers and better choices of tours when ashore.

Warnemunde, our first stop after embarking from Copenhagen, was a town unfamiliar to me because it's on Germany's eastern coast - the "wrong" side of the partition created by the Soviets, the United States, and other allies after World War II. During my Army years, I traveled around Europe, but I never imagined entering East Germany. Now, Eileen and I were eager for our first look at Berlin, a 90-minute ride from Warnemunde on the bus that would also serve for our tour, led by Konstanze, a guide who joined us in the city. The excursion we had chosen focused on the once-divided city's moves toward reunification at the end of 1989, and the fall of the Berlin Wall, after which the Soviet Union soon dissolved.

Berlin is far more than its Cold War remnants, of course. Broad boulevards took us past modern high-rises, as well as famous edifices such as the Reichstag building and the glorious Brandenburg Gate. One stretch of former Nazi government buildings, still in use by the current administration, was part of what Konstanze referred to as "the topography of terror" because of the decisions reached there before and during World War II.

After a lunch of sausages, sauerkraut, and beer, we immersed ourselves in taking photos of various segments of the Wall, many now charmingly graffiti-covered.

Other tour highlights included Checkpoint Charlie, the former station for entry into the American sector, where reenactors in period U.S. Army uniforms posed for the cameras. And there were the towering columns of the Brandenburg Gate, closed to East-West passage by the Soviets in defiance of its name.

Visiting Tempelhof Airport, we saw where the postwar airlift by the Americans, British, and French prevented the Soviets from choking off supplies to Berlin's non-Soviet sectors. There, Konstanze described the American "candy bombers": U.S. pilots who won many young German friends by dropping treats from cargo planes making their approach to Tempelhof.

After Berlin, we sailed overnight across the Baltic to Helsinki and spent the next day on a bus tour visiting a farmhouse for lunch with the family there. One more night at sea got us to St. Petersburg, where, as cruise passengers, we were permitted to disembark without Russian visas. The excursion we chose focused on Russia's czarist architecture and great art collections. As for life in the city, we hoped to learn something about that from our local tour guides.

Their descriptions, it turned out, uniformly reflected weariness with government corruption; Vladimir Putin's long tenure, effectively 15 years; and a lack of personal opportunity they perceived amid the country's financial struggles. Still, that was mixed with appreciation for the very freedom to speak their minds in such a way these days. They also praised how Russia continued to preserve and restore the treasures we were being shown.

The topic of restoration led to another theme - one that touched on the Russians' animosity toward their own, earlier occupiers: the Nazis. Restorers were the behind-the-scenes stars at two stunning palaces we visited outside the city: the Catherine Palace from 1717, and Peterhof from 1721, with terrace after terrace of fountains. Both had been all but destroyed during the Siege of Leningrad.

We devoted a whole day to St. Petersburg's Hermitage, the height of Russian opulence. Miraculously, it sustained little damage during the long German siege, when Soviet defenders kept the enemy from breaking through at the city's outskirts.

As Eileen and I strolled the expansive galleries, we felt we were wandering through a cross between the Smithsonian and the National Gallery. Crowds were large but moved at a leisurely pace, giving our tour group time to examine at length the classical European works that dominate its displays. Particularly stunning to us: a Dutch collection with 21 Rembrandt masterpieces, and Italian statuary rivaling anything we'd seen at the Vatican museum.

Back on board, we were treated to a lecture on a topic of concern for most American passengers: whether souring U.S.-Russia relations will jar us into a new Cold War. John Renninger, an adjunct professor of global affairs at New York University who spent 30 years with the United Nations, deftly blended pessimism and optimism. He hung much of his talk on the presence of an unpredictable Putin. That fit in well with Churchill's riddle-mystery-enigma description of Russia, an assessment made in 1939, Renninger noted. That was when the Soviets signed a nonaggression pact with Germany that seemed to put the European communists and fascists on the same side. (The pact collapsed when Adolf Hitler broke his promise and invaded Russia - leading, of course, to the Soviets' joining the Allies and helping to win the war.)

Churchill's full comment has this less-familiar conclusion: "But perhaps there is a key. That key is Russian national interest." The trick now for Eileen and me: using our newfound experience to help us understand what that might be.