Carolyn Marvin and David Ingle claim that nationalism is a religion.  In particular, American civil religion is a religion, sustained by violence and blood-letting, focused on the sacred “totem” of the American flag ( Blood Sacrifice and the Nation: Totem Rituals and the American Flag (Cambridge Cultural Social Studies) ).  If so, why do we expend so much industry to deny that it’s a religion?  What interests are served by the denial?  In an article on the same theme, they answer,

“Because what is obligatory for group members must be separated, as holy things are, from what is contestable.  To concede that nationalism is a religion is to expose it to challenge, to make it just the same as sectarian religion.  By explicitly denying that our national symbols and duties are sacred, we shield them from competition with sectarian symbols.  In so doing, we embrace the ancient command not to speak the sacred, ineffable name of god.  The god is inexpressible, unsayable, unknowable, beyond language.  But that god may not be refused when it calls for sacrifice.”