 After one full year of protection in the United States asylees are able to apply for green cards, and four years later, for citizenship.The recent U.S. Government policy known as "Zero-tolerance" was implemented in April 2018.In response, a number of scientific organizations released statements on the negative impact of child separation, a form of childhood trauma, on child development, including the American Psychiatric Association, the American Psychological Association, the American Academy of Pediatrics, the American Medical Association, and the Society for Research in Child Development.