Care to elaborate?
Sure. How many American soldiers and foreign civilians do you think is acceptable collateral damage to avenge one reporter's death?
The US is not the world's police. ISIS has, literally, no effect on the general American's life. It's the very definition of "not our problem." It is a catastrophic waste of life and money to go deal with some nuts who are taking part in a religious uprising in another country.
Should we go into the DPRK next? Hundreds of thousands more people are being killed and repressed there than in ISIS controlled territories. Should we go into Columbia? I mean, at some point, you just have to go "this has nothing to do with us." I'm sad a journalist was murdered but I don't think the appropriate response is a multi-billion dollar action that will kill tons of innocent people.