Iran Sanctions

The sanctions are piling on top of Iran, despite the fact that they still refuse to the nuclear program. The sanctions are set to begin on June 28th. These new sanctions prevent banks in countries that import Iranian oil from doing business here in America. And while there are 23 such countries, 11 are exempt because they are cutting back on imports from Iran. The president has said that there is enough oil outside of Iran that it won't affect oil supplies and United States allies. I wish to ask a question though: how can he believe that? Cutting off oil sales has yet to work. Combine that with  the fact that gas prices are continuing to spike, and someone like me just has to wonder if there's another way. And I'm not inclined to believe the politicians who say thats unlikely, because, let's face it, they are not experts.