At the outbreak of the Second World War, the charismatic and hugely attractive Nancy Wake was an Australian living with her French businessman husband in Marseilles. Immediately, she plunged into resistance work which resulted in her having to flee from France, leaving her husband behind.

He was rounded up and tortured horribly before being shot. He left a message for her. "Tell Nancy I love her and I didn't betray her." Burning with hatred for the Nazis, Nancy trained with the SOE and was parachuted back into France in April 1944 where she successfully led a 7000 strong army of maquisard fighters.

In her fascinating and poignant memoir, The Secret Ministry of Ag. & Fish, Noreen Riols who worked in SOE's F-section, describes how the daring and audacious Nancy admitted to taking a German officer as a lover as part of her undercover work. "Of course, I shall have to kill him," she was overheard to say - which did indeed happen. Nancy did not personally do the deed. Instead, she betrayed him which led to his execution. On another occasion, Nancy had to order the death of a so-called Dutch girl who had joined her Resistance group but who turned out to be a German agent. They had been friends. As she was taken out to die, the girl spat at Nancy and a second or two before she was shot, she looked at Nancy and said: "I am patriot too."

Leading a resistance army into the fight was one thing. These instances were another and upset Nancy deeply. However, she did not flinch from taking action to eliminate the Nazis whom she believed to be evil and wrong. In her view, nothing was more important than to rid Europe of them. Clearly, Nancy considered the means justified the end.

It was a time when circumstances were extreme, much of European civilization was under threat, and many felt that the imperative to save it for the greater good overrode normal morality and justice.

I like to think that, during the Second World War, I would have fought for the peace and democracy in which I passionately believe and would have actively joined in the fight. However, I would also have had to admit that it was complicated. For instance, if demanding and full of dangers, joining a resistance army as an unencumbered adult as Nancy Wake did is relatively simple and straightforward in its declaration of allegiances and in its intent. You are required to be brave – which must be almost impossible at times - and you are required to fight, often in unorthodox ways as Nancy undoubtedly did. In doing so, you are declaring (unless you are treacherous) that this is what you are prepared to do for the cause.

On the other hand, to be a young mother at home who is asked to shelter a fugitive on the run with possible dire consequences to her children poses - to me at least - a quite different problem. I know that when my son and daughter were young that if one hair of their head was threatened I would not have hesitated to defend them with any means at my disposal, however much I hated the oppressor – and, if that included sacrificing a friend, I think I would have done it. It’s not an easy thing to admit, and I hate to do so, but I am pretty sure that I am not alone.

Elizabeth's WWII book, I Can't Begin to Tell You, is published by Penguin and is available from Amazon. We'd love to hear your comments in the thread below.