This AMV is about war and things we are willing to do just for the "better world", "higher good", or our own ideal and beliefs. In Fullmetal Alchemist people fought because they too believed their side is the right one.
This AMV is about soldiers, common people, about ideals, believes and consequences.
Music: E Nomine - Heilig.
Lyrics of the song (In german language) and its translation can be found here: http://www.songmeanings.net/songs/view/3530822107858702296/