Ok, the translation seems a little odd to me, but is that because this would be justified usually by a second clause such as "the citizen is afraid to not fight the enemy... (because he worries he is a coward)/(because if he does not fight he fears what the enemy would do to him and his family) ?
Perhaps. It is a grammatical sentence all on its own, but it does seem like a weird statement to make. Some extra context would certainly be helpful. Maybe someone just asked, "Why does he keep fighting and never tries any other tactics?" Your suggestions are also good possibilities. There are a number of sentences in this course that require you to imagine some sort of crazy context.