A correction on behalf of major news agencies

Sunnis and Shi'ites are not ethnic groups. What we have in Iraq is not ethnic strife, unless the term is used to describe conflict between Kurds and Iraqi Arabs. Sunni and Shi'ite refer to different interpretations of Islam, or mostly...well, read the Wikipedia entry. On top of that, the tensions between Sunnis and Shi'ites in Iraq are more political than religiously based.

You might also be interested to know that Iraq is in the minority as a majority Shi'ite state. Most majority Muslim states have a Sunni majority.

Also, Iranians are not Arabs.

I hope this was educational.