U-Boats and Bullshit
Even more illustrative of BdU staff’s limitations was their reaction to the revelation of the ULTRA secret. In a report dated 10 August 1943 and noted in the BdU war diary three days later, the German Abwehr office in Switzerland broke the war’s greatest intelligence secret: “Over the last few months the enemy has succeeded in decrypting German naval ciphers, including orders to operational U-boats. All orders have been read by the enemy.” Although acutely aware of the long history of suspected and investigated cipher compromise, and despite the tabulation that Allied aircraft had struck at twenty-three of thirty-one radio-arranged refueling or other rendezvous since the beginning of June, Godt and his colleagues again deferred to the naval communications experts who pronounced the ciphers inviolable. The BdU himself remained unconvinced about a systematic decryption but approved minor improvements in the key words and cipher settings and once again further restricted the dissemination of classified information.

This vital intelligence, a rare gift-wrapped package that briefly neutralized the German disadvantages… came at precisely the right moment for a critical reevaluation of the U-boat effort. The heavy losses suffered through the period March-August 1943, which forced a U-boat withdrawal from the North Atlantic battle and all but eliminated the tanker fleet necessary for extended operations, together with the drying up of signals intelligence after the change in Allied convoy codes in June, underscored the need for a change in strategy and goals… Instead Bdu resolved to renew the convoy battles with nothing beyond torpedoes… That the revelation of cipher compromise slipped through the cracks without a closer examination - there is no indication that Donitz saw this intelligence - constitutes a serious error in critical judgment. Rather than overconfidence or arrogance (except, perhaps, for the naval communications experts), it suggests the exhaustion of the BdU staff in merely passing along an oft-raised question to presumed experts for a predictable rejection.

Neither Sharks Nor Wolves, Tim Mulligan

(via navalenigma)