I have just finished reading an analysis on this situation and have found that, according to this account at least, the capability to escort the bombers to ALL their targets existed from the outset.
It was due to General Eaker's (name - spelling??) belief in the bombers to defend themselves. Even in the face of the losses that often occurred. Apparently, he was given access to P38's, which were capable of escorting all the way to the targets and were certainly, at least a near match for the Bf109 etc.
It is mentioned that at this period during the war in Europe (say late '42 - mid early '44), the P38's had little else to do except for those that were designated for PR.
So why, if it's true, did this idiot allow the needless deaths thousands of flight crew?
When he was in command of the 8th Air Force, General Ira Eaker did not believe the bombers needed escort. He thought that the bombers' defensive armament would be protection enough. High rates of losses never deterred him from this belief. Accordingly, Eaker turned down the P-38 Lightnings provided him to protect his bombers. The P-38s, with enough range to escort the bombers to any of their targets, spent time in England with relatively little to do, and many were subsequently sent to Africa.
Thoughts?????