The German squadron pursuing convoy PQ 17 turned back due to the operation's riskiness and because the convoy had ceased to exist as a unified entity.
Notes on verification
Corroborated by Wikipedia, Fandom military history wiki, and HistoryNet; multiple independent sources support both the risk-aversion and convoy-scattering rationale for the German recall.
Sources
- Attack on the battleship Tirpitz by submarine K-21 (en.wikipedia.org)
- https://military-history.fandom.com/wiki/Operation_R%C3%B6sselsprung_(1942) (military-history.fandom.com)
- https://historynet.com/world-war-ii-convoy-pq-17/ (historynet.com)