This past Thursday the U.S. Navy rescued Iranians from Somalian pirates. Proving that Iran can't handle their own domestic affairs. My guess is the Iranian government is humiliated by this. If they can't even rescue their own people from pirates, why are they telling the U.S. navy to, " Vacate the Persian Gulf." Iran needs to look at things clearly and realize that they need the U.S. and going to war with them, even though it might improve their economy a little bit, is an unwise decision. Source - http://news.yahoo.com/blogs/envoy/u-navy-rescues-iranians-somali-pirates-183323968.html
Iran barely has a navy bar outdated boats and some recent patrol boats. Anyway the Americans were kind enough to let the iranian people go, much unlike what would happen if an Iranian navy ship rescued israeli's / Americans / Other infidels.