Phil Klay, a Marine veteran and the author of “Redeployment,” a collection of short stories about the wars in Iraq and Afghanistan, said he had little problem with most of Mr. Kelly’s remarks, but took umbrage at his restrictions on the questioning.

“If the problem is that most Americans aren’t engaged, then saying that only those who are engaged can ask about this, then that is deeply counterproductive,” Mr. Klay said in an interview. “This is deeply critical to us as a nation, and war is a huge part of what this country does.”

It is common for veterans to return from Iraq and Afghanistan to a United States largely unaware of the wars they have just finished fighting. College classes can be awkward, and questions at Thanksgiving about what happened on the battlefield are hard to answer. At the peak of the Iraq war, a picture of a dry erase board spread widely among the military, a rallying cry of sorts for those who prided themselves on being the United States’ “warrior caste.” The board contained three lines: “America is not at war. The Marine Corps is at war; America is at the mall.”

In a speech in St. Louis in 2010, after his son was killed, Mr. Kelly said something similar: “America as a whole is certainly not at war. Not as a country. Not as a people. Today, only a tiny fraction — less than a percent — shoulder the burden of fear and sacrifice, and they shoulder it for the rest of us.”

The small number of active-duty troops is not a failing but a policy decision based on the size of the force required to defend the country, said Kori Schake, a former national security aide to President George W. Bush and a defense policy expert at Stanford University’s Hoover Institution. Mr. Kelly’s remarks, she said, invoked a sense of pity for those who have not served in the military, but were dangerous because they did not seem to place value on other forms of public service.

“On the one hand, he spoke with enormous moral clarity about the horrible burden Gold Star families experience and how that burden is very far removed from most Americans when we have such a small volunteer force,” Ms. Schake said. “At the same time, he did widen the civilian-military gap.”