Pentagon Press Secretary Peter Cook had been blunter on Thursday: “Our mission in Iraq is the train, advise and assist mission. This was a unique circumstance. … This was a support mission in which they were providing support to the Kurdistan Regional Government. U.S. forces are not in an active combat mission in Iraq.”

But before Carter left the podium on Friday, he offered this explanation for why he couldn’t reveal more details of Wheeler’s actions: “This is combat. Things are complicated.”

Indeed.

The rules of the official advise-and-assist mission meant the Americans were to “stay behind the last covered and concealed position,” but when the fighters they were supporting began taking fire and casualties, they stepped in and acted. As Pentagon spokesman Colonel Steve Warren noted from Baghdad, “In the chaos of combat, when you see your friends being hit, I would submit to you that you’re under somewhat of a moral obligation.” Again, combat.

Thursday’s events have thrust into the public spotlight the rather plastic definitions of “war” and “combat” with which Americans have been operating for a while now. And not just in Iraq and Syria. Officially, combat operations ended in Afghanistan in December 2014. In May, Obama noted that “for many of us, this Memorial Day is especially meaningful; it is the first since our war in Afghanistan came to an end. Today is the first Memorial Day in 14 years that the United States is not engaged in a major ground war.”

And yet as of today, America has sustained 14 casualties in Afghanistan since Obama’s speech, including four deaths the Pentagon labels as “killed in action.” Even if the official mission of U.S. troops is to support Afghan forces, American lives are on the line and in combat theaters. American forces serving in Afghanistan are eligible to earn the Afghanistan Campaign Medal.

The U.S. may not by name or distinction be a nation at war, and it may not be a nation whose troops are part of full-scale, on-the-ground combat operations. But the men and women serving in Iraq, Syria, and Afghanistan are indeed at war whether or not America is.

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