A picture obtained from Iran’s ISNA news agency shows supporters of Iranian Foreign Minister Mohammad Javad Zarif (portrait) flashing the sign for victory as the foreign minister arrived at Tehran’s Mehrabad Airport after talks in Geneva in which world powers reached an agreement with Iran over its nuclear programme on November 24, 2013. Analysts praised a ground-breaking interim deal with Iran to rein in its nuclear program in return for sanctions relief, but warned negotiations for a full agreement will prove even tougher. AFP PHOTO/ISNA/ARASH KHAMOOSHIARASH KHAMOOSHI/AFP/Getty Images Oil prices tumbled on Monday after Iran agreed a historic agreement with world powers to halt its uranium enrichment programme, lifting hopes for a relaxation of geopolitical risk and a boost in oil supplies. Meanwhile, US President Barack Obama and David Cameron, UK prime minister, sought to reassure Israel that the accord would not threaten […]