I'll simply repeat what I quoted a week ago...
The UN Non-Proliferation of Nuclear Weapons Treaty makes it clear in Article IV:
1. Nothing in this Treaty shall be interpreted as affecting the inalienable right of all the Parties to the Treaty to develop research, production and use of nuclear energy for peaceful purposes without discrimination and in conformity with Articles I and II of this Treaty.
2. All the Parties to the Treaty undertake to facilitate, and have the right to participate in, the fullest possible exchange of equipment, materials and scientific and technological information for the peaceful uses of nuclear energy. Parties to the Treaty in a position to do so shall also co-operate in contributing alone or together with other States or international organizations to the further development of the applications of nuclear energy for peaceful purposes, especially in the territories of non-nuclear-weapon States Party to the Treaty, with due consideration for the needs of the developing areas of the world.
Is it Iran's right to develop nuclear technology for peaceful purposes, or is it the right of the USA to block their development by only assuming that Iran is planning to use it for sinister purposes?
Just answer that one question -- Is it Iran's right to develop it, or the USA's right to block it? And if you can, base your answer according to International Law.