GPS June 30th

An exclusive interview with Pres. Obama's National Security Adviser Tom Donilon. In his last day on the job, Donilon talks frankly about the search for Edward Snowden, Iran's nuclear program, Syria's crisis, and more. Then, the conservative case for gay marriage. In 1989, Andrew Sullivan wrote an influential essay advocating the right for gays to marry; 24 years on, he discusses the long journey to this week's Supreme Court decision. Finally, Blackstone CEO Stephen Schwartzman on his new Rhodes-like scholarship program, which sends students to China.