The reactor building of the Bushehr nuclear power plant in southern Iran. Indirect talks between Iran and the U.S. on reviving the 2015 nuclear deal ended without a breakthrough on Wednesday, with no date set for negotiations to continue. The two-day talks in Doha, Qatar, the first since multilateral discussions in Vienna stalled in mid-March, represent the latest setback for diplomatic efforts to roll back Iran’s nuclear program, damping already low expectations that the 2015 agreement can be restored.