Magari sbaglio, ma questa mi sembra solo una versione di un canto settecentesco già presente sulle CCG come Le petit roi de Sardaigne [Gironfla]...

O no?

This song is absolutely NOT an anti-war song. It's a traditional french military song speaking about the bleak truth of what duty means.
Which is very typical of many french military song, which unlike in other cultures, that often speak of war/sacrifice for glory or better tomorrows, speak of dying in battle, with all it's harsh reality, brutally and completely unrewarded, bringing only grief for the loved ones, as one's fulfillment of it's patriotic call.

It's french republican spirit to it's core and why that song among many other of the same type (all "departure" songs have the same elements) are still sung to this day by the french military (which sings a lot and make new ones regularly).