Lighter - surely the song is addressed to a man who is thinking of joining the army. The singer is telling him that he risks death if he goes to fight in Flanders.

The singer might be a mate, a girl or perhaps an older, more experienced person, say, his mother or father.

The use of the name/term Mally remains unexplained. But it would make sense if you considered it to be an equivalent of 'marra'.