Reality can be harsh. In order for the United States to weaken and eventually defeat the Islamic State in Syria and Iraq, it could use help from both the Iranian regime and that of President Bashar al Assad in Syria. In the Middle East, it takes illiberal forces to defeat an even more illiberal force. The mullahs' Iran and al Assad's Syria sadly represent the material at hand, with which the United States must somehow work or tolerate, however surreptitiously, however much it will deny it at the same time. Ah, you might say, What about the moderate, liberal opposition in Syria? Answer: Such forces are more viable on paper than on the battlefield.
The truth is understood but cannot always be admitted, either by officials or by journalists -- the truth being that order is preferable to disorder, meaning dictatorship is preferable to chaos, even if dictatorship itself has often been the root cause of such chaos.
The Islamic State is the fruit of chaos. It arose in a vacuum of authority. That vacuum was created by both the weakening of an absolutist (albeit secular-trending) regime in Syria and the inability of a stable, power-sharing system to take hold in Iraq following America's dismantling of Saddam Hussein's own repressive rule. And the worse the chaos, the more extreme will be the reaction. Thus, from the conflicts in Syria and Iraq that together have killed many hundreds of thousands of people and have featured a plethora of armed groups, the Islamic State has emerged in all its horrifying barbarity.