On the night of 13th to 14th February, 1945, the allied air forces bombed the historic German city of Dresden.
"It was an art treasure. It was a wedding cake. It was a beautiful thing," said American novelist Kurt Vonnegut.
Mr. Vonnegut witnessed one of the heaviest air raids of the Second World War. He had been taken prisoner of war by the Germans in 1944, during the Battle of the Bulge - Hitler's last major offensive against the allied forces.
"We were working in a plant that made syrup laced with vitamins for pregnant women," Mr. Vonnegut said. Under the Geneva Convention, we couldn't do any work associated with armaments."
He says the prisoners could hear the bombs falling on nearby German cities, but the guards told them Dresden would not be targeted because only industrial and military centers were bombed.
In fact, the city of six-hundred-thousand residents and as many refugees had not even built adequate air-raid shelters. Mr. Vonnegut says he and about a hundred other American prisoners of war were luckier than most.
"It turned out we had a swell air-raid shelter because we were quartered in a slaughterhouse. And there was this wonderful, very deep cellar under there, where they hung meat, where it was cool, and so that's why we survived. That's why we weren't killed and everybody in our immediate neighborhood was dead."
Kurt Vonnegut's 1969 novel "Slaughterhouse Five" is based on his Dresden experience. He says it took him more than twenty years to learn the extent of the Dresden tragedy. About 60-thousand Dresden residents and perhaps twice as many refugees perished in the bomb fire, which reduced the city, known as Florence on the Elbe, to rubble.
During World War Two, the allies dropped altogether about one-and-a half million tons of bombs on Germany, killing more than 6,000 civilians, including about 80,000 children and turning hundreds of cities to rubble.
"World War Two was the last mass war. It was a war of masses, a war in which mass numbers, mass vehicles, mass civilian participation in the factories was vital."
Dennis Showalter is professor of history at Colorado College.
"I think World War Two was unique because it developed a strategy of attritional-conventional bombing that was designed to destroy or cripple the industry supporting a high-tech modern war and by extension the civilian morale - the civilian effectiveness - that in an environment of total war was considered as important as the fighting men.
The early failures of the British Royal Air Force led to the development of a tactic called area bombing. Instead of trying to hit a strategic target and risk losing a bomber to the German air defense, the planes would fly at a higher altitude and drop a heavy load of bombs to destroy a whole area around targets such as railway stations, factories, mines and others. The British also developed incendiary bombs, which continued destruction long after the planes had left.
James Corum, professor of comparative military studies at the U-S Air Force School of Air and Space, says German air raids on cities such as London, Coventry, Warsaw, Rotterdam and Belgrade were small in comparison.
"Dispassionate research, and we are talking about what the British are saying about the bombing of Coventry today, is that - looking back - it was clearly a military target, one, and two, the only mistake the Germans made was not coming back and bombing it again a few more times."
However, professor Corum points out the failure of the German Luftwaffe to level the cities it bombed was due to inferior technology -- not a lack of will. But for decades after the war, Germans did not dwell on their suffering or their guilt. No major literary works focused on intimate tragedies resulting from the massacre of people in their homes.
Jack James, director of the American Institute for the Contemporary German Studies, says the most obvious reason for this silence has been the enormous pain Nazi Germany caused other people. So the post-war Germans focused on reconstruction and establishing their country as a western democracy.
"But certainly, trying to re-instate the sense of morals and values. That required an enormous distancing from what the Nazis had done," Mr. James said. "So I think that there was just simply no real national interest in digging this up except for the pockets of activity and the groups that did. But for the most part, for these five decades or four decades, the Germans were happy to say we don't want to talk about it."
This attitude has gradually changed. James Corum says over the years, Germans have written hundreds of history books detailing the death toll as well as the loss of historic buildings and monuments in the allied air raids.
"It's usually done on the local level by local historians. I am looking at one right now, which is on the bombing of Wurtzburg," Mr. Corum said.
In the last few years, the media, books and public forums have focused more attention on the human tragedy of the massive air raids.
In his new book "The Fire," German historian Joerg Friedrich raises questions about the necessity and even morality of the deliberate destruction of cities such as Hamburg, Cologne and Dresden and their civilian population.
German Nobel laureate Gunter Grass has recently published a novel about the German refugee ship "Wilhelm Gustloff," torpedoed by a Soviet submarine in 1945. The author condemns the unnecessary death of some seven-thousand people, mostly civilians and injured soldiers fleeing Poland. Questions have also been raised about post-war expulsions of German minorities from their homelands outside Germany.
Jack James says one reason for the current revision of World War Two bombing of Germany is the curiosity of the new generation of Germans, free of the guilt their grandparents might have felt.
"And maybe driven by some people who do have this sense of - we didn't really talk about that dimension ever openly because it was not politically correct," Mr. James said. "And now they are beginning to say is it (not) politically correct to talk about 50, 60, 70-thousand people who were killed in the bombing raids. Is it not politically correct to talk about that?"
Many analysts say the air raids on German cities, in which about 40-thousand allied planes were downed and about 160-thousand airmen killed, did not achieve their goal of destroying Germany's war industry, shattering the morale of the German people and facilitating the allied victory.
"Not one person got out of a concentration camp one second earlier, not one German soldier retreated one minute earlier," American author Kurt Vonnegut said. "If only one person on the whole face of the earth benefited from the fire bombing of Dresden, that was me. And I got five dollars for every person killed."
In some characteristic cynicism, Mr. Vonnegut refers to the proceeds from his war novel. Many historians today agree with his assessment. But some contend that even in 1945, Germany was a danger to the rest of the world and the allies used every means available at the time to bring it to its knees.
American historians Dennis Showalter and James Corum say the new generation of Germans are right to re-examine their history, but they must do it in that context.