Whenever President Obama makes a major foreign policy move, as he did last night announcing limited airstrikes in Iraq, it's inevitable that someone will ask, "Well, what about [X country that is also mired in conflict]?" The go-to example is Syria, where innocent civilians are being killed in the thousands in a full-blown civil war that the Obama administration has long kept at arm's length.
But the Iraq mission is special. As Obama made clear, this authorization of force has modest goals: 1) to protect U.S. personnel in the Kurdish city of Erbil and 2) to facilitate a humanitarian mission for 40,000 Yazidi Iraqis who are trapped without food or water and face imminent slaughter at the hands of the Islamic State in Iraq and Syria. There is no equivalent situation in Syria with such clear, executable goals.
Furthermore, the Iraqi government is a U.S. ally, as is the regional government in Kurdistan, where the latest action is happening. The U.S. has an interest in bolstering the regime and keeping it together; that is not the case in Syria. While Obama said he would prefer the Iraqi government to take the lead in this endeavor, the U.S.'s hand was forced after ISIS took advantage of gridlock in Baghdad to sow chaos in Kurdistan, which had once been an oasis of stability in Iraq.
Finally, the U.S. is partly to blame for the situation in Iraq. This is what happens when you recklessly invade other countries.
Could these airstrikes be the beginning of a slippery slope, drawing the U.S. into the kind of morass it has sought to avoid in Syria? Perhaps. But at the moment, the two countries represent distinct foreign policy challenges for the administration.