Opinion: Does Obama propose to destroy the Islamic State, or merely defeat it?

Exactly what is President Obama’s goal as he escalates the U.S. fight against the Islamic State, the extremist group that has seized a swath of territory in northern Syria and Iraq?

Is it to “destroy” the group, or to “defeat” it -- not exactly the same thing? Or is it merely to “shrink [it] to the point where it is a manageable problem?”

Over the last week, Obama has used all those words. In a single news conference on Friday, he used “defeat,” “dismantle” and “destroy” as if they were interchangeable.

Except they’re not.

The U.S. military, for example, makes careful distinctions among those words. The Army’s field manual on tactics says defeat occurs “when an enemy force has temporarily or permanently lost the physical means or the will to fight.” If enemy forces’ morale collapses and they stop fighting, they’re defeated -- even if they haven’t been physically destroyed.

But destroying an adversary may be tougher, because it means “physically render[ing] an enemy force combat ineffective.”

That’s why the Pentagon prefers “defeating” an enemy as its goal: It’s more flexible -- and more doable.

In the case of the Islamic State, also known as the Islamic State of Iraq and the Levant, the official U.S. goal is to “degrade and ultimately defeat” the militant group, a senior official told me -- but Obama has taken to throwing in “destroy” for good measure.

Why? Presumably because it sounds fiercer at a time when Obama’s critics have accused him of being insufficiently warlike.

The irony is that, in practice, the most accurate description of the U.S. goal is probably the mildest -- the one conservatives howled about when Obama used it last week: “to shrink ISIL’s sphere of influence, its effectiveness, its financing, its military capabilities to the point where it is a manageable problem.”

If you listen closely, even when Obama uses bellicose words such as “destroy,” sooner or later he returns to that more realistic formula.

As he said at the end of the NATO summit in Wales last week: “You initially push them back. You systematically degrade their capabilities. You narrow their scope of action. You slowly shrink the space, the territory that they may control. You take out their leadership. And over time, they are not able to conduct the same kinds of terrorist attacks as they once could.”

That sounds less ferocious than “destroy.” But it’s much more achievable -- and it’s all we’re really after.

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