So much hatred for Shia/Sunni each other no wonder muslims are being pounded by every one. I am a muslim I don't have any problem with Shia or Sunni. I know my faith very well and don't want to label myself with one. If Irans Shia wants to spread their views of islam so is Sunnis countries doing. As long as it is done peacefully with reasoning without any politics in it people will decide in the end. I think Islam by itself is sect free. Sects are man made and politics was involved from the beginning till date. Since muslims have been living in this sectarian culture and are not willing to get rid of it, they better then try to accept each other and live peacefully and don't let a common enemy use them against each other.
Now, comming to United Nations of Islam question. The best thing would be for now to built a strong ecnomicaaly independent Pakistan with great islamic philosphy of tollerance for each other and then move on to greater challenges.
Sunni muslim countries are ignorant, and are not that interested to counter shia or question on the way they have been persecuting the sunnis living in their countries, not letting them practice freely, whereas their agents ask for more freedoms in sunni countries to spread their faith.
Sunnis don't curse anyone after they complete their prayers or other religious activities, what shias do not against judaism or chistianity but against symbols of sunni islam. Saudi Arabia does'nt have small consulates in Multan like Iranians do, just to preach hatred against mainstream islam. Their faith is specifically designed to spread hatred against manstream Islam, amongst their followers, as instilling hatred is regarded the best way to keep their followers from keeping away from the mainstream muslim practices.
Shiism is all about hatred, and barbaric practices like matam,mutah, is'nt about a sect[as sect does differ but does'nt preach hatred against another sect], it's another religion that has nothing to do with islam. The most unfortunate example is Iraq where children are being slaughtered just for having names Ayesha and Umar.