Today is the anniversary of the 20 July 1944 attempt by German Army officers and elements of the German resistance to assassinate Adolf Hitler at his deep-woods hide-out in the Führerhauptquartier Wolfsschanze ("Fuhrer Headquarters 'Wolf's Lair'"), located near Rastenburg in East Prussia. Unfortunately, the plot failed: a bomb, hidden in a briefcase full of papers carried into Hitler's daily military situation conference by Oberst Claus Schenk Graf von Stauffenberg - failed to kill Hitler.
The plot was bigger, however, than a not-so-simple assassination attempt: the explosion triggered Fall Walküre (Operation Valkyrie) -- an attempt to overthrow the Nazi government by coup d'etat under the cover of a military contingency plan for army rule in the event of a breakdown of law and order.
As William Shirer later wrote, the "devil's hand" protected the Führer that day. The conspirators were dogged at every turn by plain bad luck. Hitler's daily conference, normally held in an underground air raid shelter (which would have magnified the effect of the blast), was, on this hot day, moved to an above-ground building. A colonel in Hitler's conference tripped over Count Stauffenberg's bomb-briefcase, so the unlucky colonel moved it behind one of the conference table's heavy wooden supports, on the side away from Hitler. The blast at 12:45 p.m. killed the colonel, among others, but Hitler survived with superficial wounds.
Once the explosion occurred, other conspirators in the Wolf's Lair's communications center failed to destroy the transmitting facilities. (Hitler out of communication that day was probably almost as good as Hitler dead).
Without confirmation of Hitler's death, the plotters in Berlin hesitated, fatally, to move. Had the coup began as soon as news of the explosion was received, enough of officialdom might have been induced to become too deeply involved in the plot to reverse course even given Hitler's survival. As it was, the coup in Berlin did not get under way until after 4 p.m., when Stauffenberg, (who had taken off for Berlin after planting his bomb), arrived in the city.
Only then did German Army headquarters begin transmitting a message, which began: "The Führer Adolf Hitler is dead. . ." The message did not specify the cause, but stated that a band of non-military conspirators were stabbing the fighting front in the back and that consequently, the Army was taking power. Orders were issued to arrest Nazi Party, SS and Gestapo officials, and this process began, but it was being carried out by officers and troops who believed that Hitler was dead. . .
Unfortunately, the Wolf's Lair could still transmit the news that Hitler had survived, and the plot collapsed. Graf von Stauffenberg and his closest collaborators were perhaps fortunate: shot by firing squad in the early morning hours of 21 July in the courtyard of General Staff headquarters in the Bendlerstrasse. The immediate execution of von Stauffenberg and the others was ordered by a general trying to cover up his own involvement (unsuccessfully, he was later executed also). Others implicated in the plot were handed over to the infamous Volksgerichtshof ("People's Court") where they received kangaroo trials before being executed by hanging, many with piano wire, in Plötzensee Prison, their executions filmed for Hitler's delectation.
About 5,000 persons were arrested for some kind of involvement or complicity in the plot. At least 200 persons were executed, the most senior being a Field Marshal, Erwin von Witzleben. (Generalfeldmarschall von Witzleben was one of the earliest of the anti-Hitler plotters, his disapproval of and plotting against the Nazi regime dating to at least 1934).
Field Marshal Erwin Rommel, only tangentally involved in the conspiracy -- was induced by threats to his family to take his own life. Field Marshal Günther von Kluge also escaped the hangman by suicide: although he was not directly involved in the various anti-Hitler conspiracies, von Kluge allowed plotting to go on in his headquarters.
The 20 July plot's failure is one of the more intriguing "what if's" of the Second World War. The failure of the plot destroyed the German resistance, for all practical purposes; and eliminated the political power of the traditionalist-conservative military leadership class, which had always regarded Hitler with some distaste (which he returned with interest). The plot certainly increased mutual distrust between the Army and the Nazi Party (no bad thing from the point of view of the war).