The Azeri Mirage
Jim Henley notes an emerging talking point among the "bomb Iran" crowd, focused on the fact that Iran is only very slightly over half Persian. This leads them to conclude that we could, perhaps, try to wreak ethno-sectarian division on Iran and plunge that country into Iraq-style chaos. If you look at living conditions in Iraq, you'll immediately conclude that this is a pretty immoral approach. If you look at social conditions in Iran, you'll also conclude that this isn't going to work.
Iran's Kurdish minority is legitimately mobilizable, but that's only 7 percent of the population. The whole game in terms of Iranian ethnic minorities is the Azeri population, which at 25 percent or so of the total is very large and, in fact, exceeds the population of Azerbaijan. The trouble, from a fomenting-dissent point of view, is that Azeris are very well-integrated into Iranian society. You may, for example, have heard of Muhammed Khatami, Iran's most recent former president. He's half Azeri. More to the point, you may have heard of Ali Khameini, Supreme Leader of Iran. He's Azeri. As is the current Minister of Energy, and various leading Iranian cultural figures.
That's by no means to say that Azeris are all supporters of the regime. Obviously, the regime has many Persian opponents as well as Persian supporters. The Azeris, however, are just like that. Well-integrated into overall Iranian society, with many in various degrees of opposition while many others are leading figures in the regime itself.