There is No Evidence for a Secret Weaponization Program
First of all, the question of "Should Iran be allowed to have nuclear power?" is, in my opinion, the wrong question.
Iran has signed the Nuclear Non-proliferation Treaty, has abided by its first three articles about not violating the Treaty and, therefore, is entitled to nuclear power and nuclear technology. The first three articles of the NPT describe the commitments of a member state and the conditions under which the NPT may be violated:
If a member state secretly develops non-peaceful use of nuclear technology; aid another member state to do so, or transfer its nuclear technology to a non-member state. According to all the reports by the International Atomic Energy Agency, Iran has done neither of the above. To date, there has never been a shred of evidence that Iran has or had a secret weaponization program.
By the way, it is the United States that will be violating the NPT soon, once it starts transferring its nuclear technology to India, a nation that has not signed the NPT.

He's said it repeatedly. If that were our president, we'd impeach him on grounds of insanity. If the UN were what it claims to be it would sanction Iran.
A country sitting on top of one of the world's largest concentrations of crude oil -- exporting millions of barrles to Russia -- needs nuclear power why? Environmental reasons? Sorry, a country that hangs gay men and stones rape victims caring about the planet just doesn't fit.
That famous gotcha phrase was supposedly from his speech on Oct 26, 2005. Fortunately, the NYT compiled a transcript here http://www.nytimes.com/2005/10/30/weekinreview/30iran.html where it says: "Our dear Imam [Khomeini] said that the occupying regime must be wiped off the map and this was a very wise statement. We cannot compromise over the issue of Palestine."
The word Regime was then by someone quoted as Israel and the rumor spread as a wildfire... and we know how people like to verify the sources, don't we?!
Merriam-Webster defines Regime as: "a regular pattern of occurrence" , "mode of rule or management" "a form of government", ... Not a reference to a country, let alone its people at all.
Second: Iran does not export oil to Russia... it would be silly, since Russia is a major Oil exporter too. The main bulk of the Iranian oil goes to (in this order): Japan, China, South Korea, Italy, Spain, Greece, France... ( http://www.eia.doe.gov/cabs/Iran/Oil.html )
And finally, they do however violate human rights left and right, but so does Arabia Saudi and we don't have a problem being cozy with billions of dollars on high tech weapons... heck, the US violated human right internally too up till the 60s!!! Externally still does now... if not asks those sent to Egypt for "extraordinary rendition" how they were treated? They ones who can still tell, that is...
In a separate post, i will put the rebuttal to what your post should have been only... "needs nuclear power why? Environmental reasons?"... THAT is what this debate was intended for and not the machinations around it.
Should Iran Possess nuclear weapons??
Should Priests be allowed to molest young boys and go unaccounted??
If and when Iran gets enough enriched uranium life as Israel currently knows it will cease to exist, and that willaffect the entire world.
Just food for thought from someone that has spent many years in the Middle East and understand the Muslim culture as much as I am permitted as an infidel.
Iran doesn't want nuclear weapons, they want nuclear energy . Do you understand which way the wind blows? Weather goes from west to east. If Iran ever got a nuclear bomb they couldn't use it against Israel without nuking themselves.