The White House says President Obama let Russian leaders know he would be willing to consider scrapping construction of a missile shield in eastern Europe if Russia pressures Iran to give up its nuclear ambitions. Russia has already rejected the idea, but what should we make of Obama’s overture? What message is he sending on this issue? What pressure could Russia place on Iran? Can Iran be persuaded not to complete a nuclear weapon? And how far away is a missile shield? We ask Karna Small Bodman, former senior director of the National Security Council in the Reagan administration.