A U.S. Army list of warning signs for radicalization, obtained by Wired, gives the impression that it would be impossible to distinguish a normal U.S. solider from a budding young terror suspect.
Wired notes some particularly vague "Risk Factors for Radicalization" among soldiers:
“Youth,” which might be a difficult thing to mitigate against, unless the military wants to take former Pentagon official Rosa Brooks’ unorthodox recruitment advice. “Social Networks” is another, and it’s probably alarmingly coterminous with Youth. Still others: “Emotional Vulnerability,” “Personal Connection to a Grievance” and “Conflict at Work or at Home.”