The Enemy of my Enemy.

But returning to their POW camps, the Americans carried a conviction that they had just witnessed overwhelming proof of Soviet guilt. The corpses’ advanced state of decay told them the killings took place much earlier in the war, when the Soviets still controlled the area…The evidence that did the most to convince them was the good state of the men’s boots and clothing: That told them the men had not lived long after being captured.

Newly-released documents tell of how America learned of the 1940 Katyn Massacre seventy-two years ago, and worked to keep it quiet. “The directive was to ‘never to speak about a secret message on Katyn.’ During the 1951-52 Congressional hearings, for example, no material was presented to demonstrate that Washington knew about Katyn as early as it did.