Robert Malley, the lead negotiator trying to resurrect the Iran nuclear deal, told the Senate that its chances are “tenuous, at best.” This comes after moments of promise in Vienna, where the US and Iran have worked on a potential agreement for months, but this may now be the end. The World’s host Marco Werman speaks with Mark Fitzpatrick, a former acting Deputy US Assistant Secretary of State for Nonproliferation who has followed the ups and downs of the deal closely.