Case-Study II — Mid-1942 to Mid-1943

Abstract

By the middle of 1943 - in fact by the end of May - an important point had been reached in the Battle of the Atlantic. This period saw the end of the large-scale convoy battles which had characterised much of the previous year and although Donitz at the time saw his withdrawal from such tactics as a temporary state of affairs while he regrouped and re-equipped his battered submarine fleet, U-boats were never again to attain the same degree of actual as opposed to potential threat as they had during several prolonged periods in the last four years of war. But this was a judgement which could only be made with the benefit of hindsight enjoyed by historians and, to a lesser extent, operational analysts. The Allied path in the Atlantic from mid-1943 onwards for the remaining years of war was still to be a tough one and sometimes even hard-fought. 1943 thus has a Janus-like quality and two stories about it come together in the middle of the year. The first concerns the causation of the climax reached in May; the what, how and why of that remarkable outcome, and in this the role of Ultra forms a part of the account and analysis. The second deals with what happened next - not until the end of the war, but for the next few months, and in this too Ultra deserves evaluation and attention.