The Iranian leadership had a message for Washington on Wednesday: If President Obama really wants some cooperation on stabilizing Iraq, he might first think about speeding forward with a permanent deal over Iran ’s nuclear capability. That statement by President Hassan Rouhani’s chief of staff, Mohammad Nahavandian, to reporters at an international relations forum in Oslo, hardly surprised the American and European negotiators. They are growing skeptical that a deal both Mr. Obama and Mr. Rouhani can embrace — and sell at home — is possible by a deadline agreed upon with the Iranians last year, now a little more than a month away. “The Iranians desperately needed leverage,” one European negotiator said Wednesday after weeks of arguments over how many centrifuges Iran would be permitted to keep spinning, and how fast the sanctions that have so crippled the economic lives of ordinary Iranians could be lifted. […]