As John Walker Lindh walks out of prison, we have to figure out what awaits him

The message arrived as we were passing through airport security. A US returnee from ISIS-held territory needed help. Reintegrating back into his American community was not going well. His past was doggedly blocking his prospects for the future. And the same drivers that often push people into extremist groups -- isolation, trauma and societal marginalization -- were weighing on him once again.