After 13 years of stalemated wars against al-Qaeda and the Taliban, Washington is in no position to ignore the much more powerful IS that now controls a third of the territory in two countries ? larger than Great Britain and inhabited by 6 million people. This most powerful jihadist organization is the unanticipated byproduct of America's ill-conceived imperial misadventures in the Islamic world.

Step by Step since IS's startling early June takeover of Mosul, Iraq's second city, President Obama has been incrementally increasing US involvement while awaiting sufficient political backing at home and broad international support to launch a war on the IS.