Paul Pillar observes that the ridiculous anti-containment resolution, S. Res. 380, makes completely unreasonable demands that Iran could never accept:

The new resolution—despite ostensibly aiming for an agreement with Iran—would damage the prospects for negotiating any such agreement. The resolution calls for terms that are understandably non-starters for Iran. In referring to “the full and sustained suspension of all uranium enrichment-related and reprocessing activities,” the resolution appears to rule out an Iranian enrichment program under international supervision and inspection, which almost certainly would have to be part of any formula that could gain the agreement of both Iran and the western powers. Incredibly, the resolution also calls for “the verified end of Iran’s ballistic missile programs.” This goes beyond any United Nations resolutions on Iran, which talk about nuclear capability of missiles, and even beyond anything ever demanded of Saddam Hussein’s Iraq, for which range limits were imposed. It would be understandable if Tehran reads such language as further evidence that the United States is interested not in any negotiated agreement but instead only in regime change.

The goal of any provocative ultimatum is to make such excessive demands that there is no way that the other government could ever agree to all of them without suffering complete humiliation. Undermining a possible negotiated settlement is the purpose of the resolution as far as many of the resolution’s co-sponsors are concerned. By declaring containment to be intolerable as an alternative, the co-sponsors are doing their best to make war with Iran unavoidable.