"Really its not sad or hard to understand, the only reason the BBC transmitted the Coded messages's before the D-Day invasion was to ensure that the Germans did not defeat the Russians. It was important that the Russians won, the media could have cared less about the Western Allies."
Ah, but the Russians were well on their way to defeating the Germans in the East. The Allied invasion and push into Western Europe prevented Stalin from sweeping all the way to the Channel! With no opposition, Stalin would have taken Northern Italy and Scandinavia as well.
Therefore, the BBC WOULD have slipped D-Day plans to the Abwehr hoping for an Allied disaster much greater than Dieppe. Depending upon the severity of the defeat, the Allies could not mount a new invasion for another year in which time Stalin could bypass Berlin, race to the Rhine from the East and invade France.
IMHO, the real reason for D-Day was to prevent just that! Churchill knew what Stalin was about, even if Roosevelt didn't really know or chose not to, or was, as is most likely, sympathetic toward his 'Uncle Joe'.