Some songs are just songs, others are anthems to an era, this is the latter. Some songs are a blend of instruments, others are dominated by one instrument, this is the latter.
In the 60s, it looked like nuclear war but this song isn’t really about that, methinks, though it became a theme of his. It was more about that protest generation which was so against exploitation of the earth for profit but then, he says, that generation lost its way, which is interesting, as the song was written for the 1974 album, so he already sees the Boomers as having lost their way?
Here are extracts from two comments which seem to me close to the mark on what this song is about:
I saw Jackson Browne at the Santa Cruz Civic Auditorium last night, and he closed with this song as the second encore.