What inspired Bob Dylan to write the song "Masters of War"?

This may interest you:

"Masters of War" startles Dylan himself. "I've never really written
anything like that before," he recalls. "I don't sing songs which hope
people will die, but I couldn't help it in this one. The song is a
sort of striking out, a reaction to the last straw, a feeling of what
can you do?" The rage (which is as much anguish as it is anger) is a
away of catharsis, a way of getting temporary relief from the heavy
feeling of impotence that affects many who cannot understand a
civilization which juggles it's own means for oblivion and calls that
performance an act toward peace.

http://www.bobdylan.com/linernotes/freewheelin.html