The NPT has clauses that permit the signatories to acquire nuclear technology for peaceful energy purposes (including enrichment) as long as they refrain from developing nuclear weapons. The US argument is that there is no clear demarcation line between enrichment for energy and acquiring weapons. It is only a matter of the degree of enrichment ranging from 5% to 95%. Another equally important clause of the treaty requires the P-5 nuclear states to abolish their weapons.
Human nature being what it is, no nuclear weapon state has made the slightest attempt to do so. Even Britain, a declining second rate power with no threat has just decided to upgrade its Trident submarines at the cost of hundreds of billions of dollars. Britain faces no nuclear or conventional threat and could use the resources to benefit its population in social welfare. The nostalgia of past empire and to justify retaining its UN permanent seat, it is loathe to disarm. The same nostalgic desire of fading self-importance made Blair (Bush's poodle) to synchronously bark with his master's roar and pounce on Iraq by lying about its WMDs and falsifying intelligence reports.
India refuse to sign the NPT and acquiesce to nuclear apartheid from the beginning. Pakistan with its severe psychopathology of sib rivalry and some security justification did the same as did Israel for security reasons. India's Homi Bhabha had trained with Bohr in Copenhagen and understood the concepts and technology of the bomb. India, using plutonium diverted from its CANDU reactor, acquired the expertise of the bomb on its own, as did the America at first and originally, and Russia and France subsequently. Britain obtained the technology from the US and China to some extent with Soviet help. France proliferated the technology to Israel and China to Pakistan. In fairness, the bulk of the US scientists responsible for nuclear weapons were Jewish and the Israelis may have also trained under them.
The problem is the sole superpower, America does not want to allow unfriendly nations to have nuclear weapons. Strategically this is understandable but morally and legally invalid. The strong do as they wish and the weak do what they must.
The analogy of Dhruva comes to mind. As a child he saw his stepbrother sitting on his father's lap and tried to do the same. His stepmother who was there prevented him from doing so and told him that his desire would have been fulfilled if he had been from her womb. The hurt child retreated, did penance and acquired an even higher status. India tried to do the same and not surprisingly the Indian experimental reactor was named Dhruva.
India is not the only dedicated enterprising country and others can take the same path. That brings us to two characters of the Mahabharata who did so. Eklavya learnt archery on his own from a statue of Drona and Karna denied by Drona, masqueraded as a Brahmin and learnt archery from Parshurama. When Drona found out that Eklavya was as capable as Arjuna, he demanded the thumb of Eklavya as his fee and deprived Eklavya of ever using a bow with this single stroke. Incidentally, he secretly taught his son Ashwatthama the use of Brahmaastra (WMD) which the son used on pregnant Uttara, as Pakistan may some day use it on the womb of India.
Karna after being found out was by the parochial Parshurama, was cursed that he would forget his skills at a critical point in life and was slain by the establishment candidate Arjuna.
The US strategy in getting India to sign the civilian nuclear treaty is to emasculate it in a similar manner by making it dependent on uranium supply from it and Australia, ban reprocessing and nuclear testing and stop becoming independent by use of thorium breeder reactors. Once the treaty is signed and India invests five billion dollars for buying each US reactor (20 are planned), the huge financial outlay and the need for uranium will make India a hostage unable to deviate from American dictates in foreign or economic policy. This is why the US and Israel wish to bomb Iran's nuclear facilities if economic pressure fails. Pakistan will suffer a similar fate sooner or later.
The US is justifiably worried that a nuclear Iran may because of its pan-Islamic ideology use its nuclear weapon irrespective of the consequences. As Al Qaeeda boasts, they love death while the West loves life. Iran is hampered by being Shia, a despised minority by the Sunni Ummah. It is at the fork and schizophrenic about whether it wants to be a nation state or an ideological ummah. The problem began with the prophet who sowed the idea of a Muslim Ummah based on religion and transgressing beyond nation states based on language, ethnicity or geography. That is why we have Muslim fifth columnists in India assisting Pakistani terrorist groups, British and Spanish Muslims bombing trains and subways and worried France, Germany, Denmark and Netherlands with large Muslim minorities. America should know better. It used nuclear weapons unnecessarily against a Japan on the verge of defeat under the false pretext of saving American lives. It also put US citizens of Japanese descent into concentration camps while doing nothing of the sort to those of German or Italian descent.
Chomsky puts it beautifully when he says that a sole superpower hegemon is like a Mafia boss. He cannot tolerate dissent or bucking by even a single small shopkeeper refusing to pay extortion. This is why the US has terrorized and isolated Cuba economically on the basis of its communism while making deals with China and Russia the big former communist powers. This is why it engineered regime changes in Afghanistan, Bolivia, Chile, Congo, Dominican Republic, Grenada, Guatemala, Hawaii, Haiti, Honduras, Iran, Iraq, Nicaragua, Panama, Somalia Venezuela, Zimbabwe etc.
The attack on Iraq and a future possible one on Iran can best be understood by studying ancient history from the second millennium BC and especially the dialogue between the Athenian envoy and the leader of Melos at the beginning of the Peloponnesian War in the fifth century BC. Interested readers can refer to my previous article about hypocrisy in international relations.