Prior to World War II, the Ardeatine Caves were mined for the volcanic material known as tuff for use in cement production. But by March 24, 1944, production had long since ceased. On that day, torches inside the cave's corridors and hollows provided makeshift lighting. Outside, in the afternoon sun, trucks were hauling prisoners to the site -- a total of 335 men, the youngest of whom was only 15. They were all Italian.

The German occupiers wanted to avenge an attack that communist partisans had carried out a day earlier on a German police unit in Rome's Via Rasella. The victims of this retaliatory act were chosen at random. Most of them had been imprisoned in a Gestapo jail in the Italian capital or were being detained by the Wehrmacht, Germany's Nazi-era military. None of them had been involved in the attack....

[E]ven if it continues to be publicly commemorated to this day, neither German nor Italian officials had any interest in bringing its perpetrators to justice. Indeed, the only person to be punished for it was Herbert Kappler, the SS officer in charge of German police and security services in Rome during the war. He was sentenced to life in prison in 1948.

While researching why officials have been so reluctant to punish these crimes in the political archives of Germany's Foreign Ministry, Berlin-based historian Felix Bohr stumbled upon a spectacular set of documents, which he published earlier this week on an Internet portal for historians.

The documents entail an exchange of letters begun in 1959 between officials at the German Embassy in Rome and their counterparts at the Foreign Ministry in Bonn, Germany's capital at the time. With unprecedented clarity, the documents testify to how German diplomats and Italian officials cooperated in shielding the soldiers in Kappler's charge from criminal prosecution. As embassy adviser Kurt von Tannstein put it, the goal was a "putting (the affair) to rest, as desired by both the German and Italian side."...