The United Nations Security Council at long last voted to impose sanctions on Iran for its continuing pursuit of uranium enrichment in defiance of the international community. The Tehran government immediately dismissed the U.N. move and vowed to step up nuclear activities. The stage is thus set for yet another round of protracted diplomacy, even though the record to date is dismal. Success is possible only if the world speaks with one voice to Iran. That is not happening today.

Suspicions have swirled around Iran's nuclear ambitions since 2002, when an Iranian group opposed to the Islamic government in Tehran provided information about hidden nuclear programs and facilities. Western nations, in particular America, argued that the programs were developing a bomb, claiming that an oil-rich country like Iran had no need for nuclear energy. Tehran conceded that the programs existed but insisted that its nuclear program was civilian in nature and legal under the terms of its membership in the Nuclear Nonproliferation Treaty.

The dispute has dragged on since then, with Iran slowly curtailing cooperation with the International Atomic Energy Agency (IAEA), the U.N. watchdog entrusted with ensuring that nuclear technology is not misused. Despite offers from a troika of European powers to step up political and economic engagement with Iran in exchange for the abandonment of suspect activities and despite slowly increasing U.N. pressure, Iran has stepped up nuclear-related programs, including establishing uranium-enrichment facilities essential to creating the materials for a bomb.