Defense Minister Ehud Barak said Monday that Israel cannot afford to be duped by Iranian tricks and that he had little confidence that negotiations between Iran and world powers would succeed in convincing Iran to give up trying to produce nuclear weapons, at a meeting of the Foreign Press Association in Jerusalem. Even though Barak recognized that international sanctions imposed on Iran to date were having an impact on Iran's behavior, he was not hopeful about the ultimate outcome of talks."Today sanctions are stronger than ever. They've forced the Iranians to take note, to sit down and to talk," he told the assembled journalists. However, despite any tactical progress, Barak said that he was not filled "with confidence. I may sound pessimistic but the state of Israel cannot afford to be duped."Iran is in the midst of negotiations with six world powers, known as the P5+1 grouping of diplomats from the United States, Russia, China, Britain, France and Germany. The first round of talks with Iran was in Istanbul on April 14. A second round of talks is scheduled for May 23 in Baghdad."They say a pessimist is merely an optimist with experience," he quipped.Barak also, for the first time, addressed criticism last weekend from former Shin Bet (Israel Security Agency) head Yuval Diskin.The defense minister implied that Diskin and other politicians who criticized him were sticking their heads in the sand and ignoring, as he perceives, the cold truth of the danger that Iran poses.