A diplomacy special: the 81st UNGA, the Urban 20 Summit and lobbying in lobbies

Leaders of the world flock to New York for the 81st edition of the United Nations General Assembly. Then: are US sanctions any more effective, or ethical, than military might? Plus: mayors of the world gather to swap urbanism tips. And: which hotel lobbies are best for lobbying?  See omnystudio.com/listener for privacy information.