Noah Rothman wants the U.S. to oppose ISIS and Iran:

There are no compromises available to Western nations when it comes to either the genocidal ISIS or the human-rights abusing, terrorist-supporting theocrats in Tehran. The U.S. cannot choose Iran over ISIS; it has to stop both.

Even if we agreed that it is desirable to fight against both sides of a war, it is hard to see how this is a workable policy. It is fairly clear what we mean when we are talking about “stopping” ISIS, but it isn’t at all clear what this means when it comes to Iran. Stop them from doing what exactly? To what end? At what cost? Why? Rothman never explains. It is simply taken for granted that the U.S. “has to” do this. But that’s not true, and it makes even less sense now than it used to.

Unlike most of our regional clients, Iran is actually fighting ISIS, and it is because they are doing this that their capital came under attack today. That doesn’t make them our “ally” in a formal sense, but it shows that their interests and ours are more aligned at present than are the interests of many of the states that we have been arming to the teeth for years. At the very least, that suggests that knee-jerk hostility to Iran doesn’t serve U.S. interests in the near term, and for that reason Americans shouldn’t be heeding the advice of those that insist on making that hostility a priority.