Iran has been racing to develop nuclear weapons for several years, according to the IAEA's [International Atomic Energy Agency] Nov. 2011, report.Experts, including the U.S. Secretary of Defense, estimated that Iran could develop a nuclear bomb within a few months to a year.  The UN and international leaders, from Europe to the Middle East to Asia, unequivocally oppose Iran acquiring atomic weapons. Various strategies have been considered to stop Iran's weaponization program.
Diplomacy: The UN and international leaders hoped diplomacy would persuade Iran to abandon the weapons program.
Economic sanctions: When these efforts faltered, Western leaders imposed progressively tougher economic sanctions. The sanctions have had an impact, but many experts fear their effect will be diluted because Russia and China have refused to adopt the severer policies that the US and EU imposed in Jan, 2012
Regime change: The international community would not object to a friendly, non-aggressive government in Iran complying with the Non-Proliferation Treaty and developing nuclear power for peaceful purposes. Despite the recent success of mass movements that toppled repressive regimes across the region, it is unlikely that the same will occur soon in Iran, especially given the short time before Iran is likely to develop nuclear weapons. Indeed, some officials fear that once Iran acquires such weapons, it will be even harder to dislodge the regime.
Military action: Experts also believe there is only a limited window of time when military action could be an option. Iran is burying its major nuclear installations underground where they would become impregnable to attack. In January, 2012, Israel estimated that its time frame for an effective military action is nine months; America, with its superior firepower, estimated a time frame of 15 months.
The Dilemma: The difficult question is whether, after the window for military action closes, the sanctions would work or whether Iran will withstand them, and the world will have to live with a nuclear Iran.
"We're not going to tolerate a nuclear weapon in the hands of this Iranian regime," - President Obama, Jan. 19, 2012