In February 1943 Himmler refused to act against Admiral Wilhelm Canaris after Müller presented him with evidence that the Abwehr chief had ties to the resistance. Rather than act, Müller was ordered not to pursue the case. To summarise, in late 1942 the German customs police arrested an export merchant called Major Wilhelm Schmidhuber, who worked for the Abwehr. His crime was illegal currency transactions. Canaris refused to cover for him, so under interrogation Schmidhuber hinted that the Abwehr had tried to use the Vatican as an intermediary to contact the British in winter 1939/1940. The Gestapo was brought in, and assigned an officer called Franz Xaver Sonderegger to the case. Sonderegger investigated Hans von Dohnanyi, a jurist who worked for the Abwehr and a close associate of Major General Hans Oster, the true motor behind the resistance circle in the Abwehr. While Schmidhuber’s illegal business activities were largely motivated by personal profit, Dohnanyi had used him to smuggle Jews out of Germany. Moreover, in 1939 Dohnanyi had hired Josef Müller back to try and use the Vatican as an intermediary for clandestine negotiations with the British. Sonderegger claimed in his report that Canaris had been the mastermind behind these activities. But instead of passing it on to Hitler, Himmler passed on the secret police’s findings to the Wehrmacht judiciary. Dohnanyi was arrested, and Oster removed from his post. This crippled the resistance in the Abwehr, but the agency itself was spared for the time being and Canaris remained in command. Later Himmler also ignored evidence from his own agency that Canaris was deceiving the Reich leadership by giving them false intelligence about Italy's loyalty to the Axis following the overthrow of Mussolini.
Moreover, Himmler met Johannes Popitz, Prussian finance minister and member of the conservative resistance, and Carl Langbehn, a lawyer who was a personal friend of Himmler and also had ties to the resistance, on 26 August 1943. The meeting is mentioned by Ulrich von Hassell, a German diplomat and potential foreign minister for the Schwarze Kapelle, in his diary. Popitz and Langbehn were frustrated by the resistance's inability to win over a major commander. Prior to the meeting, Olbricht brought Tresckow and Popitz together for a chat, at which Langbehn was also present. The German historian Peter Hoffmann, a specialist on the history of the resistance, writes that Tresckow appears to have given the idea of approaching Himmler his blessing. Marie-Lousie- Sarre, who worked on the staff of Army Group Centre and occasionally served as a courier for the resistance, recalls that Field Marshal Fedor von Bock considered a Wehrmacht coup to be doomed to failure without SS support and stated he would only act if the conspirators managed to enlist Himmler.
It's a bit ambiguous what was discussed, but Popitz appears to have tried to persuade Himmler that peace talks needed to be conducted with the Allies and that changes in government would be needed. Langbehn, who wanted him to be more frank, was disappointed by this. However, Karl Wolff promised to arrange another meeting. Popitz turned to General Olbricht to enquire about which general could be entrusted with the leadership of the Wehrmacht in the event of a coup. Olbricht suggested Field Marshal Erwin von Witzleben, who had been one of the leading figures in the September conspiracy during the Sudeten Crisis. Witzleben declared he was ready to assist if Himmler approached him on his own initiative and committed himself.
Popitz informed Hassell about his meeting with Himmler. According to Popitz Himmler hadn’t committed himself but shown an open mind. Hassell suggested a meeting between him and Wolff. In a diary entry Hassell expressed his distaste for the idea of working with the SS and stated it could only be a temporary solution but noted that any means were justified to avert catastrophe.
As Hoffmann writes, the attempt to enlist Himmler, however tentatively, took place because the resistance lacked resolute leadership or a general willing and able to act. Oster had been dismissed, which deprived the resistance group of the Abwehr of its engine. Canaris would assist the resistance and screen its activities, but not take direct action. Beck was ill, and in any event commanded no troops. Witzleben was no political leader, and while Tresckow had the drive and energy, he was far from the centre of power. Olbricht held a crucial post in Berlin, but lacked the initiative and in any case had no command authority without Fromm’s approval. Thus, the attempt to reach out to Himmler occurred at a time when the conservative opposition was beset by setbacks and crippled by paralysis.
Regardless, after the meeting Langbehn travelled to Switzerland to meet Allied representatives. There he met a representative of Dulles. Himmler appears to have been aware of his mission. However, upon his return, Langbehn was arrested by the Gestapo. This didn't lead to a full-on purge though. Hassell presumed that the Gestapo and Müller acted on their own initiative, and Himmler was covering his tracks. Hassell assumed that the Gestapo had been able to intercept the message of a British agent, which described Langbehn as Himmler’s confidante in Switzerland and further noted that Himmler understood Germany’s situation and was ready to negotiate. As a result, Himmler had been forced to sacrifice Langbehn to clear himself of accusations of treason. Post-20 July Himmler claimed it had been a 'sting operation'...and never bothered to say why he hadn't done about the rest of the conservative resistance after Langbehn's arrest.
It's important to stress that there's
no evidence that Himmler and the SS had any foreknowledge of the 20 July plot. Indeed, Stauffenberg and his comrades had previously aborted an earlier assassination plot because Himmler and Göring hadn't been there and they'd wanted to blow them up, too. They were in the dark about the conspiracy in the Replacement Army. Nebe was obviously part of the conspiracy, but thus far no evidence has surfaced that he was secretly informing Himmler (Nebe remained passive on 20 July, too). The fact that the bomb exploded represented a massive security failure on the part of the SS, and Kaltenbrunner was a fanatical Hitler loyalist.
Besides, the Valkyrie orders stipulated that SS installations were to be occupied, SS and police leaders arrested and the SS disarmed. So it's probably safe to presume that Himmler's contacts with the part of the resistance that was willing to utilise him died in late 1943. It's pertinent to note that while the conservative resistance as a whole was anti-democratic and authoritarian, Popitz was very much on the far-right, as was Hassell, and seems to have been marginalised by the time the coup occured.
I wrote an essay about this that discusses this whole affair in more detail.
