In “A Dearth of Feeling,” a 1996 essay for the New Criterion, Anne Applebaum made a simple but compelling observation: Americans and Western Europeans – “people who would be sickened by the thought of wearing a swastika” – nonetheless found it amusing to wear T-shirts and hats emblazoned with the hammer and sickle. Even though Westerners were “intellectually” aware that Stalin killed “at least twice as many innocent people as Hitler,” they did not react to communism with the same gut-level repugnance.

Ms. Applebaum suggested that for Western intellectuals, this “moral confusion” partially stemmed from a reluctance to re-examine old ideas. A closer look at our relationship with the Soviet Union could lead to some uncomfortable conclusions about our own moral failure at Yalta, for example. Ms. Applebaum also cannily pointed out that the “founding philosophers of the Western Left” – Marx and Engels – “were the same as those of the Soviet Union.”

Now we in the West are running out of excuses. In 2003, Ms. Applebaum published “Gulag: A History,” (Doubleday) a fascinating survey of the Soviet concentration camps. This year, Oleg V. Khlevniuk, a senior researcher at the Russian State Archives, has published “The History of the Gulag: From Collectivization to the Great Terror” (Yale University Press, 464 pages, $39.95). For anyone interested in examining the inherently corrupt nature of the Soviet regime, either book would be a good place to start.

Ms. Applebaum brilliantly synthesized memoirs and interviews to create an absorbing narrative. Mr. Khlevniuk (not surprisingly) uses a more archival approach. “The History of the Gulag” contains dozens of translations of newly available documents, from transcriptions of Stalin’s own remarks (torture is a “completely proper and appropriate method” of dealing with “enemies of the people”) to a truly depressing array of complaint letters to camp authorities (“They call us settlers, but we do not know who we are, of which country we are citizens, or what rights and responsibilities we have.”). The result is a comprehensive picture of the Gulag, an “economic-punitive machine” that destroyed millions of lives.

This massive network of labor camps began with a relatively straightforward idea: In 1929 the Politburo realized that prisoners were an untapped source of cheap labor. Inmates could be re-assigned to labor camps, in order to better exploit the country’s mineral resources. But 1929 was also the year of forced collectivization and industrialization, and the Stalinist leadership saw that these camps could also be used as a way to purge those who stood in the way – namely, priests, intellectuals, and “kulaks,” or wealthy, land-owning peasants.

By 1930 about 500,000 people were forcibly relocated to labor camps and settlements. Some 1.8 million were deported in the following year. Another huge expansion of the Gulag system accompanied the famine of 1931. By the spring of 1933, the Soviet Union had about half a million prisoners in labor camps alone, not including those in prison or jail – another 250,000 – or the six or seven million “kulaks and saboteurs of grain procurement” dead or dying of hunger.

The pattern was repeated again during the Great Terror of 1937-38, when Stalin turned his attention to those who could supposedly serve as foreign agents or saboteurs in the coming war. This was, in essence, a purge of those with differing nationalities: first those with a German background were arrested; a larger operation against Poles followed. The long list of other groups targeted for repression – including Latvians, Greeks, and Koreans – would be laughable if it hadn’t led to so much misery and blood.

Mr. Khlevniuk estimates that “several hundred thousand” people were deported to labor camps or settlements during the Great Terror. About 1.5 million people were sentenced to prison, and almost 700,000 people were executed. According to Mr. Khlevniuk, by 1941, the Soviets had “about 4 million people in all Gulag divisions,” with perhaps 2 million more “engaged in corrective labor.” Thus it is possible that almost every family in the Soviet Union had someone with a direct experience of repression at the hands of their authorities. The Gulag had also become an enormous economic factor for the country, with significant proportions of the national output of timber, gold, and coal coming from what was essentially slave labor.

But I wonder how much we have learned, in the West or the East. Last year in Poland, I frequently saw college students wearing “C.C.C.P.” jackets; here in New York, “The Motorcycle Diaries” prompted a brief resurgence of those T-shirts bearing Che Guevara’s hirsute image. And Russia is reportedly planning two new monuments to the World War II – each featuring a statue of Stalin. One will be in Moscow; another, in what is at best a colossal lapse in taste, will be in the Belgorod region, near Russia’s border with the Ukraine.