photo - EPA/Michael Reynolds
US Congresswoman Marcy Kaptur, who was instrumental in bringing about the release of the documents, called the Monday ceremony a “momentous occasion.”
Nevertheless, aside from the good will gesture from US authorities, historians in both America and Poland generally noted that there were no startling revelations as regards US knowledge of Soviet culpability for the crime.
Many of the approximately 1000 documents had been available to historians prior to yesterday's ceremony.
“I do not think that these documents particularly change our general understanding of U.S. policy on Katyn,” said Harvard professor Mark Kramer in an interview with the Polish Press Agency.
“They basically confirm what we know, that many of the representatives of the U.S. and Britain knew early on that it was the Soviet Union that was responsible for the murders.”
Over 22,000 Polish citizens, largely reserve officers, were executed in April 1940 by the Soviet secret police (NKVD).
The killings took place at several points across the Soviet Union, including at the Katyn Forest near Smolensk.
It was not until after the fall of the Iron Curtain in 1989 that Moscow formally admitted responsibility for Katyn, having previously pinned the blame on Nazi Germany.
During the war, Washington and London were concerned not to rupture ties with their ally in Moscow, as British documents also underline.
“The documents show the internal discussions and debates as to whether the U.S. government should reveal the truth in a time of war,” Kramer added.
“There were people - not senior officers, but State Department officials and our embassy in Moscow - who wanted to say what we all know.
“Roosevelt, however, was not willing to. But this is not anything new,” Kramer concluded.
A letter from Polish Foreign Minister Radoslaw Sikorski was read out at yesterday's ceremony on Capitol Hill, thanking Congresswoman Kaptur for her perseverance, and the United States National Archives for their work in aiding the process.
In spite of a post-war US report (completed but not revealed to the public in 1952) that again affirmed Soviet culpability, the US government remained silent on the conclusions for several decades.
US historian Allen Paul, author of a major work on Katyn, believes that United States authorities should apologise to Poland.
“It's high time that we issued an apology or a statement to Poland expressing our deepest regrets,” he said.
“The concealment of the truth about Katyn delayed for many years Americans' understanding of the true nature of Stalinism," he added.(nh)
The interview with Allen Paul was conducted by Polish Radio correspondent Michal Kubicki.