I have expressed no view about events before the German invasions, so why quote Macmillan on that?

Here are some more relevant quotes from her, covering all my 3 points, and the fact that historiography has moved on.

"Yet far more novels and memoirs at the time were either ambivalent about the rightness or otherwise of the war or, indeed, saw it as something that had had to be fought. And not everyone who had been in the war wanted to forget it."

"Now is surely the right time to challenge the accepted views. The wartime generals were not all cowards and incompetents as Alan Clark argued in his infamous The Donkeys (1961). A new generation of British historians, among others, has done much to explode such lazy generalisation and show that commanders developed both strategies and tactics that, in the end, worked. And was the war just a dreadful mistake or was it about something? At the time people on all sides thought they had a just cause. It is condescending and wrong to think they were hoodwinked. British soldiers felt they were fighting for their country and its values; "

http://www.ft.com/cms/s/2/7b6f0490-6347-11e3-a87d-00144feabdc0.html