Robert C O’Brien (pictured left) is currently the State Department’s special presidential envoy for hostage affairs. A founding partner of the Los Angeles-based law firm Larson O’Brien.NYT – Mr. O’Brien served with Mr. Bolton when he was President George W. Bush’s ambassador to the United Nations and has advised Republican candidates like Mitt Romney, Scott Walker and Ted Cruz. In both the Bush and Obama administrations, Mr. O’Brien worked on an initiative to train lawyers and judges in Afghanistan. (link)
People describe O’Brien as similar to his friend John Bolton without the virulent twitchy trigger finger. In his capacity as special envoy for hostage affairs, O’Brien wrote a letter to Swedish prosecutors urging them to release A$AP Rocky. According to CBS O’Brien’s work “on Rocky’s case endeared him to Jared Kushner, the president’s son-in-law and one of his top advisers.”
CBS’s Margaret Brennan gives a good outline here: