When Churchill ordered the Balkans campaign, O' Connor was in the midst of a string of successive victories, trouncing the Italians in North Africa. The Balkans campaign removed at least 50,000 of his troops, not to mention supplies, vehicles, and equipment. Losing a significant number of them in the campaign and Crete also worsened the situation. I can't find any reason why Churchill would cancel the campaign, but that isn't my real speculation here. Assuming O' Connor had the extra troops, how far do you think he could have gotten? Would Hitler still have sent Rommel, if O' Connor seemed to leave no chance for Italian victory? Another question, if O' Connor did not lose his troops, it is likely that he would not have lost at Tobruk and be captured. As such, how well would he perform the rest of the war, if not in the hands of the Axis? Judging by his conduct up to that point in the war, was he a promising military leader? EDIT: I may be giving too much credit to O' Connor, and not enough to his superiors.