Call to Secure Nuclear Material at Seoul Summit

World leaders have called for closer cooperation to tackle the threat of nuclear terrorism at a summit on nuclear security in Seoul, South Korea. President Obama is among the world leaders in attendance. At the end of the summit there was a joint call to secure “vulnerable nuclear material”. Lucy Williamson, a correspondent for our partner the BBC, joins us to discuss the Seoul summit and Obama’s private meeting with Pakistani Prime Minister Yousaf Raza Gillani.