That is the essence of Stephen Kinzer's provocative article in the American Prospect. It's worth reading in full but the jist of it is that unlike the Gulf monarchies and Presidents-for-Life that we currently accommodate, Iran and Turkey have democratic traditions and Iran especially has a population that craves democracy and is nominally pro-American. Turkey is emerging as a major power in the Middle East and Iran's power, while still hobbled by sanctions and tyrannical rule, is latent but nonetheless formidable. I'm not sure I buy the whole argument in Kinzer's piece, but I thought I'd throw it out there.
[Hat tip: Thomas Barnett]