well, much has been done and policies are being implemented, actions have been taken in order to prevent Iran from acquiring nuclear weapons.
Here I am not going into the details of what actions and policies have been taken already from UN sanctions to Unilateral embargo of the Trade by United States, and pressurizing other countries and banning multinational cooperations which go against those established Sanctions and Trade Embargo. There is no doubt that above measures have created problems for Iran from Economy to Domestic Political Problems and it certainly did delay the iran's acquisition of nuclear weapons.
However, the strategies that I propose here are a bit aggressive but covert approach towards resolving this problem. They certainly contain risks and unpredictability regarding the outcome but if implemented with caution and tactfulness, they will definitely give us the desired outcome. following are the strategies that United States Government can consider as favorable solutions to iran's problem at the moment:
1- Regime Change: The controversial presidential election of Iran in June 2009 provoked what is now known as the "Green Movement", it was basically led by Two prominent opponents of Ahmadinejad, namely Mir Hussein Mousavi and Mahdi Karroubi supported by Ahmad Khatami former president of Iran. The movement which started by mid 2009 was confined till end 2010 which was finally suppressed by brutal force and leaders of movement being under house arrest or in jail we do not know exactly. This movement which began with peaceful demonstrations ended up with violent street fights among the demonstrators and brutal force of Iranian government. It is very significant because it was the first of a series of open criticism of the regime and The Leader. More importantly it showcased a very large gap or disagreement among the ruling conservative clerics and liberal reformist clerics of Iran.
It is obvious by now that United States can not or will not be able to convince the ruling clerics to not pursue nuclear weapon by the existing strategies and policies. Hence, I propose Regime Change as most favorable option at present to achieve that end. It would have been very difficult to propose such a strategy back in the day that Iranian ruling elites were indivisible, but now we have the best opportunity to exploit and try to support the green movement to revive and challenge the government in similar way as it happened it Egypt. This would have the best outcome as it does not require any military involvement and of course no direct intervention or high economic costs. United States can easily get in touch with the leaders of green movement and cut a deal with them as they require support and in several occasions privately they have considered that if United States support them they will definitely not reject it. So, I propose United States must provide financial assistance or any public or political support the movement requires in order for them to breakdown the system and force the regime to reconcile and bring a change in regime.
2-Supporting Insurgency in Iran: There is a very popular idiom in Iran which says that "one day Iran without military, is the end of Iran as nation" it only means in Iran we have so many different ethnicities and communities that if given chance they will split the country in pieces. What I am indicating here is not any biased opinion towards iran per se but only as a possible strategy which can be implemented by the United States in order to prevent Iran from acquiring nuclear weapons. The Azeri people in Iran which have historically been suppressed and marginalized by Governments in Tehran, have several times attempted for independence or at least autonomy but have been denied by Tehran. Like wise Kurds, Arabs, Baluchs, Turkmen, Armenians, Assyrians, Jews and Georgians have all been dominated by the Persian/Iranians which have always ruled over the country. If given chance, These ethnic groups will definitely choose break a way from Iran either by creating their own nation state or by joining their own ethnic neighboring nations. Hence, given this willingness on the part of these ethnicities especially Azeris, Baluchs and Sunnis who already formed their guerilla militias, United States can very easily provide these insurgents with arms and finance in order to destabilize the country and exhaust the military and economic power of Iranian regime. This will make the task of preventing Iran from nuclear weapons very easier by either instating a friendly regime or to ask the insurgents target the nuclear sites and destroy them.
3-Targeting the Iranian Nuclear Sites by Isrealis: As a last resort I propose the United States Government must consider the targeting nuclear sites of Iran by permitting the Israeli Airforce to attack the sites which they are willing to do so without slightest US involvement, of course this should only be done after consultation with Iraq, Afghanistan, Pakistan and Saudi Arabia in order to avoid any political back clash to this initiative. This operation will have the best possible outcome if only above two strategies are implemented and a world campaign to boycott Iran in any way possible to create chaos and internal disputes among the ruling elites so they will not have the will to retaliate.
To conclude, I know that above strategies are not easy and will have the risk of starting a Bloody War in this strategic region. But, we can not achieve anything from waiting for a miracle so that Iran will stop pursuing nuclear weapons. If united states is really concerned and worried about having a nuclear Iran, then I propose that above strategies needs to be considered and implemented in order to solve this problem once and for all. Plus US not being involved in the operation, Presence of US troops in Afghanistan, Iraq and several other middle eastern countries and with having the approval of neighboring countries of Iran and world community, I do not think that Iranian military will be able to cause much of a problem than they can after they acquire nuclear weapon.