The question the military leaders have asked themselves is whether giving US troops and pilots more dangerous roles in the war against IS in Iraq is likely to generate more political support or have the opposite effect. Their pessimism on that question is based on the knowledge that such an escalation won't help defeat IS. As a senior Pentagon official told the Post: "We have become very sensitive to the idea that we don't want to risk lives and limbs if there isn't a high probability of a payoff."
The air war in Iraq and Syria is evidently expected to continue indefinitely. But the fact that the US is intervening militarily in an openly sectarian conflict without being able to affect the outcome is a fundamental political problem that is bound to come back to haunt the Obama administration and the US military.
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