Old friends

Why the title and statement Old Friends? Hornsleth describes it as follows:

“A good old friend of many lonely soldiers, the AK 47, seems to be neutral in itself. It does not know who it kills. It has no memory of its own. A weapon is a tool. A human killer is a human being. A human being can turn another human being into a dead being, a dead old friend. A friendship between a tool and man can be a long lasting relationship when your country lacks democracy and darkness seems to fall on every step you take”