The Persians have not been happy with their Arab neighbors since the seventh century when Persia was invaded by Arab Muslim armies.
Now we have a more public confrontation between Iran and the United Arab Emirates when Mahmoud Ahmadinejad, president of Iran, made visit to a disputed tiny island of Abu Musu which is 47 miles from the Iranian coast and claimed by UAE and Iran.
Iranian nationalism responds happily to this short of think and keeps the Iranian government in a good light with the population.
Abu Musu occupies a commanding position near the mouth of the Strait of Hormuz which see a fifth of all oil transported by ships pass through this coke point.
The Emirates have nothing to fear from Iran because the Gulf Cooperation Council, led by Saudi Arabia, will offset any precipitous move by Iran. This is not to mention the U.S. navy and air power in the region.