WW2

 
Stalin and Ribbentrop shake hands after the signing of the Molotov - Ribbentrop Pact with the scary looking Shaposhnikov laughing it up in the background, Moscow, August 23, 1939.

Stalin died 60 years ago today.  He had a stroke in the night, and lay in a pool of urine on the cold floor of his dacha for hours until he was dead.  Beria made sure nobody went in to help him until it was too late.  Not that I'm expressing sympathy.  The world became a better place when he died.  My thoughts about Stalin in a previous article.

This is a revealing photograph, a rare instance of Stalin letting his guard down.  It shows a greedy wolf contemplating a huge meal.   In this case, the meal was Stalin's favorite: Poland.  Significantly, the photo exists because it was taken by a German photographer brought along to the signing by Ribbentrop.  A Soviet photographer would have destroyed the negative rather than risk showing the great leader in an unflattering light.

There is a continuing debate in Russia about what to think of Stalin.  Some praise him for his wartime leadership.  Others condemn him because of his ruthless terror.  Both are right, though I think his crimes far outweigh his achievements. He was, however, the essential man in World War II.  Had he lost his nerve in the summer and fall of 1941, the Germans would have won the war.

Edits for clarity. 

Update:
Stalin did actually lose his nerve in July.  As the enormity of his errors became clear to him, he left the Kremlin and hid out at his dacha for two weeks.  When a delegation came to ask him to return, he thought they had come to arrest him.  But he did go back to work, and by the end of July or early August, his nerve returned.  It never wavered again.

Also, looking at the photo, it occurs to me that Stalin is looking at Poland, and Ribbentrop is thinking, "You took the bait.  We will destroy you."

WW2

One of the actual Enigma machines smuggled out of Poland in 1939

From an intelligence point of view, the war started badly for the Germans by having their codes broken.  It went downhill from there.  Every agent they sent to Britain was caught and turned, feeding bad information back to their masters.  The German military intelligence service was full of anti-Nazis occasionally in touch with the Allies.  SS and police intelligence services under Himmler were totally ineffective.  Stalin had a cabinet level spy in the German government and occasionally knew about Hitler's decisions before the Whermacht high command.  The British were wildly successful with numerous operations designed to deceive or confuse the Germans.

But it all started with Enigma.  The Enigma was a portable cipher machine used by all branches of the Third Reich military and diplomatic corps.  It was widely thought to be unbreakable and so coded messages were routinely sent via radio.  However, the Poles started breaking Enigma messages in 1933.  Thereafter, they steadily improved their ability to decode military messages and topped their efforts by stealing several machines.  The machines were smuggled to England in September 1939, and one of these is pictured above.  There were numerous variants of the machine and each had to be broken separately.  The models used by the German Navy were particularly difficult to crack.

The Allies mounted a massive effort to break en-masse the thousands of Enigma coded messages sent by the Germans daily.  To facilitate this industrial-level decryption, they built the first computer, Colossus.  The intelligence derived from this code-breaking was called ULTRA and its existence kept secret until the 1970's. Colossus was not fully de-classified until 2000.  Other secrets remain.  The identity of Stalin's spy, for example, has never been disclosed.

There's a loving article at Wikipeida including links to online Enigma simulators.