Iran has a right to civilian nuclear power. The U.S. has no right to investigate Iran, to put sanctions on it, to threaten it, or to otherwise try to interfere with its nuclear power. And the U.S. in particular has no right and no credibility to regulate anyone when it comes to WMDs, given that the U.S. constantly violates the NPT and has had allies and client states like Israel, Iraq and others that have illegally acquired and used WMDs.
The IAEA, the organization that has the actual authority to supervise any country's nuclear capabilities, repeatedly declared that "the Agency continues to verify the non-diversion of declared nuclear material in Iran”. If action were necessary, it would occur under the auspices of the UN, not by the lawless actions of an individual state that has no legal authority and no recognized global authority to police other countries. The U.S. is not a policeman and it is not a ruler: in the global community, it is a fellow citizen with the same rights and responsibilities as other countries, nothing more.
No reasonable person wants a nuclear-armed Iran, because no reasonable person wants more nuclear-armed states in general. But no reasonable person wants a superpower threatening its rivals and violating their rights under treaties that were negotiated in good faith either. It is a sign of how few commentators in the West are reasonable human beings that so many reflexively adopted the notion that the people and government of Iran have no rights.