Abwehr

The Abwehr was the official intelligence and counterintelligence service of the German military between World War 1 and World War 2, and during the latter until it got eaten by the SS's own intelligence organization, the SD, in 1944. The name translates as "Defense" since the Abwehr's original job was to keep spies out of Germany.

The Abwehr is not remembered as a terribly competent organization, with reason. It had to fight against several rival agencies with similar competencies from the moment Hitler came to power, and as the apolitical alternative in the highly political atmosphere of Nazi Germany, it had to fight these battles at a disadvantage. It produced perhaps one great success story, but even this was largely wasted in that it could not be exploited for much of anything.

It was lead by Admiral Wilhem Canaris, who is mainly remembered for having either been a part of or aware of and tacitly supporting the German Resistance against Hitler.

Although his membership is not widely known, the most notable Abwehr agent by a long shot is none other than Oskar Schindler

Tropes include

 * Chew Toy: Honestly, the Abwehr seems to have been everybody's Chew Toy. It was unloved by everyone and Canaris was not considered an effective leader or forceful enough to fight the opposing agencies for resources and jobs.
 * Defector From Decadence: A number of Abwehr agents did this. Histories of the organization note that many people who volunteered to spy for them simply wanted to get out of Germany. Others, including some of what they thought were some of their best agents during the war, had always intended to betray them at the first possible opportunity and acted as double agents from the moment they were recruited.
 * Enemy Civil War: The Abwehr vs SD.
 * La Résistance: While not actively engaged as an organization in this, a large number of the Abwehr's leadership up to and including Canaris were involved in or aware of and took no action against the German Resistance.
 * The Mole: The greatest example in history of organized Moledom in history, the British captured and turned every German agent in the UK, creating the Double-Cross System to manage them all and manipulate German perceptions.
 * My Country, Right or Wrong: Inverted. They rationalized their behavior by distinguishing Germany from the Nazi government; thus, the country wasn't wrong, but the leaders were completely insane and pretty much counted as the enemy. Consequently, they had less-than-realistic hopes for Allied peace terms and hoped that the bulk of Germany's empire and strength could be maintained.
 * Obfuscating Stupidity: The Abwehr are barely remembered to this day and certainly not with the same dreaded reputation as the Gestapo or the SD; for many who do, including those formerly in British Intelligence, they were regarded as an incompetent joke who may as well have been sabotaging their own operations....except, of course, they were, since they were effectively being run by the anti-Nazi resistance. Which may count as Double Subverted, if you think that means they were really incompetent, to have become so compromised as that.
 * The Rival: To the SD, the Intelligence bureau of the SS, founded and headed by Reinhard Heydrich, who was something of A Pupil of Mine Until He Turned to Evil for Canaris, who regarded him (correctly) as their most dangerous and calculating opponent.
 * The Valet Did It : The legendary agent Cicero gave the Germans information. He was a valet of the British ambassador.
 * Cicero may have been reporting to the SD rather then the Abwehr.