As Russia's government pulled out all the stops on May 9 to celebrate the Soviet victory over Nazi Germany and to remember the estimated 25 million Soviets who died during the war, historian Konstantin Bogoslavsky was working to shed light on the fate of Soviet POWs "abandoned" by their own government.

The savagery of Hitler's war on the Soviet Union is widely documented, but many details remain elusive about the plight of Red Army prisoners.

Their exact number will never be known for sure, but estimates of Soviet Red Army soldiers taken prisoner during World War II range from 4 million to 6 million. About two-thirds of those captured by the Germans -- more than 3 million troops -- had died by the time their comrades captured Berlin in May 1945.

The Soviet Union was the only country that refused to cooperate with the Red Cross and did not even allow Red Cross delegations onto its territory."

The archives of the Soviet People's Commissariat of Foreign Affairs were recently digitized, and Bogoslavsky has been studying the wartime correspondence between the Soviet government and the International Committee of the Red Cross, the Geneva-based international organization that tried to aid prisoners, the wounded, and refugees during the war.

"Already on June 23, 1941, the Red Cross sent a telegram to [Soviet Foreign Minister Vyacheslav] Molotov offering its assistance to the Soviet Union during the war," Bogoslavsky told RFE/RL. "Molotov confirmed his interest."

In the first weeks of the conflict, Germany and the Soviet Union both confirmed they would adhere to international conventions on the treatment of prisoners. However, it quickly became clear that neither side intended to keep its commitment.

In the first six months of the war, as the Germans raced across the Soviet Union to the outskirts of Moscow, more than 3 million Red Army soldiers were taken prisoner, often as a result of encirclement as Soviet officials refused to allow them to retreat or failed even to issue orders.

According to the archival materials, Bogoslavsky said, the Axis powers offered to exchange lists of prisoners with the Soviets in December 1941. Molotov's deputy, Andrei Vyshinsky, wrote to his boss that a list of German prisoners had been compiled and advised that it be released to prevent harm to the Soviet Union's reputation.

"But Molotov wrote on the message, '...don't send the lists (the Germans are violating legal and other norms),'" Bogoslavsky said. "After that, almost all the letters and telegrams received from the Red Cross...were marked by Molotov as 'Do Not Respond.'"

The Soviet government adopted this policy as a result of a cold-blooded calculus.

"By the end of 1941, more than 3 million people had been taken prisoner, and one of the Soviet leadership's goals was to control this avalanche," Bogoslavsky said. "A Soviet soldier had to understand that if he was captured, he wouldn't be getting any food parcels from the Red Cross and he wouldn't be sending any postcards to his loved ones. He had to know that the only thing awaiting him there was inevitable death."

Stalin's government, in my opinion, was guilty of not giving moral support or material assistance to its own soldiers, who were simply abandoned."

One Soviet document issued under Stalin's signature, the historian noted, asserted that "the panic-monger, the coward, and the deserter are worse than the enemy."

In addition, the Soviet government refused to allow any Red Cross representatives into its own notorious prison camps, where they might stumble on secrets of Stalin's prewar repressions.

"The distribution of food and medicine to prisoners was carried out by representatives of the Red Cross, and that would have meant allowing them access to camps in the Soviet Union," Bogoslavsky said. "The Soviet leadership was categorically opposed to that. Despite numerous requests, Red Cross representatives were never given visas to travel to the Soviet Union."

"Of course, the entire responsibility for the mass deaths of Soviet prisoners must fall on the leadership of the Third Reich," he added. "But Stalin's government, in my opinion, was guilty of not giving moral support or material assistance to its own soldiers, who were simply abandoned."

In March 1943, Molotov wrote a letter to U.S. Ambassador to the Soviet Union William Standley, who had forwarded an offer from the Vatican to facilitate an exchange of information about Soviet prisoners being held by the Germans.

"I have the honor of reporting that at the present time this matter does not interest the Soviet government," Molotov wrote. "Conveying to the government of the United States our gratitude for its attention to Soviet prisoners, I ask you to accept my assurances of my most profound respect for you, Mr. Ambassador."

During the course of the war, the Soviet government also refused to cooperate with the governments of German allies Finland and Romania on the prisoners issue. Soviet prisoners in Finland did receive Red Cross packages that were organized by a charity in Switzerland and distributed in Finland on a unilateral basis.

In 1942, Romania offered to release 1,018 of the worst-off Soviet prisoners in exchange for a list of Romanians being held by the Soviet Union.

"The Soviet leadership simply ignored that offer," Bogoslavsky said.

"The Soviet Union was the only country that refused to cooperate with the Red Cross and did not even allow Red Cross delegations onto its territory," he added. "Germany did not work with the Red Cross in connection with Soviet prisoners, but it did cooperate concerning those of its Western enemies -- the Americans, the British, and the French."

The misfortunes of many Soviet POWs did not end when the guns fell silent.

"It is a myth that all those who returned from POW camps were sent to the gulag," Bogoslavsky said. "The NKVD (Soviet secret police) set up special camps for checking and filtering returning prisoners. According to historian [Viktor] Zemskov, about 1.5 million former prisoners passed through the filtration process. Of them, about 245,000 were repressed."

Written by RFE/RL senior correspondent Robert Coalson based on reporting by RFE/RL Russian Service correspondent Dmitry Volchek