What are the motifs in The Monkey Wrench Gang by Edward Abbey?

The effects of the Vietnam War and its consequences run prominently through the book. Hayduke is a Vietnam veteran, and many of his current experiences relate back to his time in Vietnam. Hayduke spent fourteen months as a POW, and another two years fighting the VC for the United States. He recounts in the novel several times images that remain in his head of women and children fused together, dead, from the heat of napalm dropped on them.