If you read the actual histories, including Churchill's own accounts and biographies of Churchill, your conclusion might differ from Eric Margolis'. Churchill came up with the daring plan, sure, but the execution and implementation were botched pretty much across the board by the military commanders responsible for carrying it out. They were largely unwilling to commit to the venture with the necessary speed, focus, and commitment necessary to see it through. They kept dragging their feet, ignoring Churchill's urgings to speed up and deal with minesweeping while they still could. Basically the result was a true disaster but it really wasn't Churchill's. Churchill was the only believer in the plan, basically. So the plan was doomed. Go read the histories.