Why is it accepted for countries like us and russia to produce uranium but not iran?

"The Treaty on the Non-Proliferation of Nuclear Weapons, also Nuclear Non-Proliferation Treaty (NPT or NNPT) is a treaty to limit the spread (proliferation) of nuclear weapons. The treaty came into force on 5 March 1970, and currently there are 189 states party to the treaty, five of which are recognized as nuclear weapon states: the United States, Russia, the United Kingdom, France, and China (also the five permanent members of the United Nations Security Council)." This is why US and Russia can own Nuclear Weapons. I think it's wrong to own any nuclear weapons since nuclear weapons not only kill the target but innocent lives. People need to learn from Hiroshima and Nagasaki.