...The reader survey asked more than 2,200 active-duty troops this question: “In your opinion, do you think the U.S. military should send a substantial number of combat troops to Iraq to support the Iraqi security forces?” Slightly more than 70 percent responded: “No.”

“It’s their country, it’s their business. I don’t think major ‘boots on the ground’ is the right answer,” said one Army infantry officer and prior-enlisted soldier who deployed to Iraq three times. He responded to the survey and an interview request but, like several other service members in this story, asked not to be named because he is not authorized to discuss high-level military policy.

The Military Times survey was conducted online this summer and concluded in August just as President Obama was ramping up the air campaign against the Islamic State group.

As the U.S. expands that air war into Syria and increases the number of U.S. boots on the ground in Iraq — topping more than 1,700 total — service members say their feelings about the crisis and the U.S. response to it have intensified....