A former top diplomatic appointee in the administration of President George W. Bush will help sell the Iranian nuclear deal to House Democrats this week. Nicholas Burns, who served as undersecretary of state for political affairs from 2005 to 2008, will brief the caucus on Wednesday at the invitation of Minority Leader Nancy Pelosi (D-Calif.). Burns, who helped Bush design the current detente with Iran, is a strong proponent of the nonproliferation deal.