It’s difficult to quantify how many the Islamic State have killed in Iraq and Syria. But, along with its barbaric practices and attacks in Europe, it has generated significant blowback. The number of Islamic State fighters killed by allied airstrikes has been put at 25,000. In other words, as Al Qaeda found when its base was attacked in Afghanistan after 9/11, its misconceived attacks lead to a world of pain.

In a National Interest article titled Death and Taxes in Islamic State, John Ford writes about another threat to the Islamic State — its dwindling tax base. Besides defecting fighters due to severe pay slashes,

It drives out those who are insufficiently pure, and then denounces as traitors all Syrians who flee to Europe instead of going to Raqqa. By driving people out of its territory who can’t or won’t live under ISIS’s harsh version of sharia, ISIS is depriving itself of the tax base it needs to finance its war. ISIS’s ideology may be slowly strangling the group to death.

It’s as if the Islamic State can’t help itself. Its belief system holds that once a caliphate is established, next comes the ultimate showdown with the West. Maybe the Islamic State thinks that its short-lived caliphate has already served its purpose and it’s onward and upward to a total war in which it has no chance of prevailing.