washington advocate americans imprison iranian authorities say friday concern trump administration hard line iran would close chance talk secure prisoners release major shift u.s. policy president donald trump announce would certify iran comply 2015 nuclear deal warn might ultimately terminate agreement administration also designate iran islamic revolutionary guard corps dominant player country security economy politics terrorist group move one expert say would make group less will negotiate prisoners jason rezaian washington post reporter detain iran 18 months say twitter trump iran strategy hurt american hostages hold iran hope wrong look though americans hold hostage iran abandon realdonaldtrump rezaian write use trump twitter handle white house respond request comment state department official say unite state call immediate release u.s. citizens hold unjustly iran seven know american citizens permanent residents detain last two years iran businessman siamak namazi 81-year-old father baquer namazi princeton doctoral student xiyue wang art gallery owner karan vafadari wife afarin niasari robin reza shahini iranian-american california nizar zakka lebanese national u.s. permanent residency big frustration still u.s. government plan resolve husband prison 15 months wang wife hua qu tell reuters say new u.s. sanction make afraid husband fate show relationship deteriorate wang arrest august 2016 dissertation research sentence 10 years prison espionage charge allegations family university deny know u.s. government go engage iran qu say live terror everyday despair karim sadjadpour iran expert carnegie endowment international peace washington say conference call reporters designate irgc terrorist group would make far difficult direct line communication them irgc go much less mood engage serious negotiation unite state say sadjadpour friend namazi january 2016 obama administration secure release five americans imprison iran agree much-criticized prisoner swap protract direct talk iran months follow swap iranian government arrest several americans irgc typically entity detain interrogate americans accord family members human right group jason poblete u.s.-based attorney zakka say sanction could helpful get party talk other criticize obama administration approach iran focus enough unconditional release hostages anything move us speak clearly one another president much good flimsy talk take place poblete say advocate americans hold iran worry trump 's hard line