It's often said during wartime that "the enemy of my enemy is my friend." Nowhere in the annals of history is this more true than the uneasy alliance that was hoisted upon the United States and the Soviet Union during World War II. Now, 72 years later, the U.S. National Archives has released 1,000 declassified documents showing the extremes that the U.S. went to to ensure that the alliance would not be compromised: As early as 1943, Washington knew that the 1940 Katyn Massacre, in which 22,000 Poles were killed, was the work of Josef Stalin and not the Nazis — and deliberately suppressed the evidence.

Since the massacre, Poles have alleged that the U.S. government was involved in a coverup. The newly released documents suggest that their suspicions were correct, a surprising and upsetting revelation that some historians are calling "potentially explosive." Here's how the wartime episode unravelled, and how the history books will have to be rewritten.


Uneasy alliance

The alliance between the U.S. and U.S.S.R. was a union of sheer necessity, one propped-up on weak foundations. Back in 1939, Hitler and Stalin had connived to sign a nonaggression treaty that essentially gave the Nazis free license to romp all over Europe. But shortly after Hitler invaded Poland in late 1939, the Soviet Union conducted their own invasion of the country and occupied its eastern regions.

In an effort to consolidate their occupation, Stalin ordered the massacre of over 22,000 Poles, including military officers, police, and the intellectual elite. Rumours that the Soviets were involved trickled out of Poland and into Washington — but there was no evidence to support such a claim, and many simply refused to believe it. Moreover, if true, it would be much more convenient to blame the Nazis.


Then, in June 1941, in complete violation of the Nazi-Soviet nonaggression pact, Hitler launched a devastating surprise attack on Russia. The Soviet Union was forced to clamor back to Britain and its allies. In just a matter of a few months, the Russians were defending a front line that extended from Leningrad down to the Black Sea — a distance comparable to a line running across the continental United States.

President Roosevelt was desperate to see this Eastern Front hold, especially in consideration of Allied activities in North Africa — and their planned invasion of Western Europe. Maintaining friendly terms with the communist and despotic U.S.S.R. was seen as a necessary evil; America quickly forgot about the Red Scare and Stalin's pact with Hitler. Hollywood propaganda lauded the courageousness of the Russian people, while American factories spewed out tanks and other supplies destined for the Eastern Front.


Coded memos

By 1943, events had progressed in Europe, as had American involvement in the war. And it's at this stage that the recently declassified documents hold relevance. Vanessa Gera and Randy Herschaft of Associated Press were able to take an early look at the secret memos, and here's what they discovered:

It was May 1943 in the Katyn forest, a part of Russia the Germans had seized from the Soviets in 1941. A group of American and British POWs were taken against their will by their German captors to witness a horrifying scene at a clearing surrounded by pine trees: mass graves tightly packed with thousands of partly mummified corpses in well-tailored Polish officers uniforms.

The Americans - Capt. Donald B. Stewart and Lt. Col. John H. Van Vliet Jr. - hated the Nazis and didn't want to believe the Germans. They had seen German cruelty up close, and the Soviets, after all, were their ally. The Germans were hoping to use the POWs for propaganda, and to drive a wedge between the Soviet Union and its Western Allies.

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. They also saw Polish letters, diaries, identification tags, news clippings and other objects - none dated later than spring of 1940 - pulled from the graves. 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.


Soon after this experience, the POWs, with the help of MIS-X (a group that helped prisoners escape and transmit intelligence reports), were able to send coded messages back home — including a note by Clayton Bissell which clearly stated, "German claims regarding Katyn substantially correct in opinion of Van Vliet and myself."

Other newly released documents show that Roosevelt received a detailed report from Winston Churchill indicating what had happened in the Katyn Forest.


This newly released evidence strongly indicates that Roosevelt and other members of the top brass knew about the Katyn Massacre, but deliberately ignored it and kept the information hidden for the sake of maintaining an alliance with the Soviet Union. And by 1950, aware of the implications of hiding this information during the war, the U.S. government continued to issue a gag order on the entire affair. 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.


From a geopolitical perspective, and as historian Allen Paul told the AP, the U.S. cover-up delayed a full understanding of the true nature of Stalinism — an understanding that came only later, after the Soviets acquired the atomic bomb and set up the Iron Curtain.

And historiographically speaking, the sudden presentation of previously classified information is a potential indication that there may still be more to come. Because many of the key players have now passed on, and because they no longer face any potential recrimination for misdeeds or wrongdoings, this information is finally being released to historians and the public. The history of World War II, it would seem, has yet to be completely written.


All of the newly-released documents and maps at the National Archives can be found here.

Images via National Archives.