The French military invested much of its hope in the Maginot Line, a defensive military border designed to be impervious to attack. When the Germans broke through this line, French defeat seemed certain, leading to France’s quick surrender.
Within this context, the French had a difficult time holding onto hope of resistance. Like the refugee mother at Vianne’s door clinging to her dead infant, those who clung to the hope of resisting Nazi power seemed foolishly optimistic. Thus, when Vianne and Isabelle hear the radio broadcast about the French surrender and Isabelle says she wants to continue fighting, Vianne insists that resistance is futile.
well the "as" makes it a simile. its an exaggeration method used to emphasise a certain feeling or action. in this case its used to emphasise a feeling of grief or sadness. Hope this helps!
