European and Iranian diplomats are meeting in Geneva in a last-ditch effort to revive negotiations over Iran's nuclear enrichment program before the landmark 2015 agreement expires in October. European countries have threatened to reinstate suspended sanctions unless Iran makes significant concessions, including renewed talks, accounting for its uranium stockpile, and restoring access to international inspectors. Iran's leadership has taken a defiant stance, rejecting direct talks with the United States and warning against further military action, while challenging the Europeans' right to restore sanctions. With time running out and little optimism for a breakthrough, European officials may soon trigger the deal's snapback provisions, risking the collapse of restrictions on Iran's nuclear activities and further escalating tensions among global powers.