In this week’s edition of NEWSWEEK, R.M. Schneiderman profiles John Matthews, a Vietnam vet who went deep undercover among America’s most right-wing, anti-government extremists. "These people are just plain crazy," he says. "If they don’t like you, they [would] take you out to have you shot. They don’t care. These people think that if they overthrew the government they’d make a better world. Their world would be a total nightmare."