A nation is a body politic, that is, a projection of one’s own body. The nation (unlike actual organisms) is conceived as omnipotent, indeed immortal. Human being seek to fuse with their nations—become “one” with them—in the hope of achieving an omnipotent, immortal body.
Nationalism is relocation of the self: from one’s own body to an omnipotent body politic. One imagines one exists “out there”—participating in world historic events.
Nations want and need enemies—can’t live without them. Nations come into being by identifying an enemy against which a struggle can be waged. One may call this enemy a Jew or a communist or a terrorist—it doesn’t matter—if there is an object or class of people against which a struggle can be waged.
What distinguishes nations from other social entities or institutions is that they have the right to kill. A cursory study of history reveals that killing is what nations do best.