Talks resumed on Tehran’s nuclear program last Friday on the sidelines of the U.N. General Assembly in New York. These negotiations – the first high-level talks since an interim nuclear accord was extended in July - come amid renewed pessimism that the parties will be able to reach a deal by the November 24 deadline. The doubts were expressed in public comments this week by American, Iranian, and IAEA officials.

In a speech on Middle East policy on September 16, Under Secretary of State for Political Affairs Wendy Sherman said Iran and the P5+1 remain “far apart” on core issues, including “the size and scope of Iran’s uranium enrichment capacity.” Sherman added that a final agreement must ensure that any effort by Tehran to make nuclear weapons would be “so visible and time-consuming” as to have no chance of success. Sherman cited Iran’s centrifuges as a specific point of divergence. According to media reports, the P5+1 are insisting that Iran reduce to the low thousands the number of its operating centrifuges, and to maintain this level for at least ten years. Iran, however, remains unwilling to operate fewer than 10,000 centrifuges, which is roughly the number currently enriching uranium. It also insists that it needs to ramp up centrifuge operations within seven years.

In an effort to forge a compromise, the P5+1 proposed that Iran remove the pipes that connect their centrifuges, rather than dismantling the bulk of the 19,000 centrifuges currently installed, according to the New York Times. The proposal was immediately criticized by Republicans in Congress who, in a September 19 letter to Secretary of State John Kerry, asked for clarification on “a troubling nuclear concession.”

Iran is concerned about a possible division between the White House and Congress. Speaking at the Council on Foreign Relations on September 17, Iranian Foreign Minister Mohammad Javad Zarif complained that the West is “obsessed” by sanctions. He said these measures had become an end unto themselves, and he questioned whether Congress would acquiesce to sanctions relief as part of any final nuclear deal. His remarks followed a new round of sanctions against Iranian organizations announced by the Obama administration in late August. The targets of these measures include the suspected center of Iran’s nuclear weapons research, Iranian financial institutions, and shipping companies tied to Tehran’s national shipping line.

Another obstacle to progress in the talks is Iran’s refusal to cooperate with the IAEA’s long-standing investigation of the "potential military dimensions" of Iran’s nuclear program. Speaking to reporters on September 15, IAEA head Yukiya Amano said his agency’s investigation into these issues “would not be endless,” which was a way of suggesting that the Agency might release its own conclusions on the subject if Tehran’s cooperation is not forthcoming. The IAEA is seeking clarification from Iran regarding research on the detonation of high explosives and on neutron transport calculations – two areas with direct application to nuclear weapons.

Recent reports by private groups diverge on the importance of a full accounting of Iran’s past weapon-related research as a condition of a final deal.  A report published by the Federation of the American Scientist concluded that Iran must provide “a comprehensive declaration that is correct and complete concerning all aspects of its nuclear program both current and past.” In Foreign Policy, Jeffrey Lewis of the Center for Nonproliferation Studies argued that such a declaration is both “totally unnecessary and potentially devastating” to the chance of reaching a final deal.