Iran may be one of the focuses of President Obama’s nuclear security conference, but North Korea will certainly be front and center at the next one. Obama announced Tuesday that South Korea would host another on nuke matters in two years. The development served to underscore his point that only global cooperation could make a real impact on curbing the threat of nuclear terrorism. “Terrorist networks such as al Qaeda have tried to acquire the material for a nuclear weapon, and if they ever succeed, they would surely use it,” Obama said. Fighting terrorists, he added, “requires a new mind-set—that we summon the will, as nations, as partners, to do what this moment in history demands.” Obama earned a diplomatic victory on Monday when China agreed to put pressure on Iran’s nuclear ambitions.