Why does USA care about Iran's nuclear mission while USA has weapons of mass destruction?

What i am trying to understand is, why does USA care about iran's nuclear plan while we all know (the whole world) she has hardcore weapons of mass destruction and she keeps modifing them as days go by.

Because whack job countires should nt have nukes.

Because the U.S. is concerned how Iran will use them...

n bcoz an nuclear tragedy will effect the whole world..not only iran.

so u got to have the right tools and people to handle it! any errors and the whole world will suffer!

The main reason is that Iran and North Korea is a dictatorship run by nut balls. Only one person has to decide to detonate a nuke and it is their decision alone. Here in the US and other countries one person does not have that kind of power. It would have to be voted on in congress or Parliament.

because Iran thinks it is supposed to run this world

'cos Us think they are more responsible than Iran,witch i find really interesting.So ,who was the first and only country to use a nuclear bomb and killed thousand of people? Yes,US...

Have you ever heard about the Nuclear Non Proliferation Act and it's signatories?

Let's say at your house your neighbor on the left has guns, and the neighbors on the right has guns. The ones on the left threatens you and others to wipe you out, but the ones on the right never threaten anyone. Which house would you like to not have guns? Why is that so hard to understand?

The ragheads need to be kept in line, is why. Haven't you been paying attention, boy?

Cause if iran,or anyone who is not WITH the us have nuks,us will not be able to threaten them or give them orders or invade them,thats why .
usa knows well that anyone who have nuks,will get out of their hands,and they want all the world to do as they say,or they r terrorists and should be invaded.
its so arogant and cruel,when u tell someone that he cant have something that u already have and threaten him with,
even if usa dont use their nuks,just having them give it extra point over others,and keep others scared,and beleive me,if they needed to use it,they will.
thats the truth,and dont listen to all the bulshit excuses that ppl r saying here about dictatorship and all that,cause usa is runed by a dictator radical gov,they r invading ,killing and threatning others,and just say stupid excuses.
usa is half arogant zionists and half brainwashed ppl

It just might be because

1) the last time someone put an insulting cartoon in the paper, 50 million Americans didn't act like a bunch of uncivilized, ignoramuse, savages and try to kill everybody in sight.

2) You don't hear the government and religious leaders of the US calling for anther country to be blown off the map unlike the animals who run Iran.

I don't think it is about nuclear stuff, I think it is about control of the middle east. Oil, politics, etc. America is out to control most if not all the world, New World Order under US control.