At the end of last month, after lengthy negotiations, Turkey consented to U.S. use of its bases to mount strikes against the Islamic State. At the National Interest, Micah Zenko writes:
This latest development was characterized as a “game-changer” by a senior Obama administration official, in particular for more intensive bombing of the Islamic State in northern Syria. Rather than flying from carriers or Persian Gulf bases, flying out of Incirlik significantly increases the time that coalition strike aircraft can loiter above Islamic State-controlled territories and, potentially, provide close air support for coalition-backed opposition forces on the ground, including the Pentagon-trained rebels that entered Syria on July 12.
But
In the limited time since the United States has had expanded access to Incirlik, the devastating effects against the Islamic State have not been apparent. Turkey may be placing restrictions on which opposition force ground units the United States can support: the Turkish Foreign Minister spokesperson has said, “Support to People’s Protection Units (YPG) is not one of the elements of the agreement,” while the State Department spokesperson said the opposite two days earlier: “[YPG] have already benefited from coalition air support.” There also might be fewer readily available Islamic State targets that the F-16s and Reapers have been authorized to strike.
Nor has Turkey “conducted any additional strikes against the Islamic State in Syria.” In other words,
… the data shows that—like other purported incremental and tactical enhancements to the war against the Islamic State—access to Incirlik has not been a “game-changer.” … The wholly unrealistic strategic objective of “destroying” the Islamic State is no closer to fruition.
Re destroying the Islamic State, Zenko again, this time at Foreign Policy:
Why did Obama claim that the United States can destroy a militant army of 10,000 to 30,000 members, when few people in or out of government believe that this aspirational end state can be achieved? … Like his predecessor, Obama chose to articulate a wildly unachievable end state, rather than show the political courage to say the truth: the United States will attempt to diminish the threat that IS poses to U.S. personnel in the region to the greatest extent possible based upon the political will and resources that the United States and countries in the region are willing to commit. [Emphasis added]
Growing more cynical by the paragraph, Zenko ruefully concludes:
The only thing to be certain of when IS is not destroyed is that nobody will be held accountable, and another terrorist enemy will be put on the destruction list.
Three reasons why the Islamic State might not be going anywhere:
One, a state such as Turkey is leery of mounting a large-scale offensive for fear of inciting attacks by the Islamic State on its own soil.
Two, a state such as Saudi Arabia still clings to the belief that the Islamic State, as with Islamic militants previously, can be useful to them in destabilizing Shia states.
Three, even though, as of June, the United States claimed to have killed 10,000 Islamic State fighters, it’s still somewhat limited by concerns over civilian casualties.