Is the Chatanooga incident an act of terrorism or an act of war?

Quoting from a rather cogent, albeit jarring, commentary on Slate:

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According to local and federal officials, Thursday’s bloody assault in Chattanooga, Tennessee, was ruthless and deranged. The U.S. attorney says investigators are treating the attacks, committed by a lone gunman at a military recruiting station and a Navy and Marine Corps Reserve center, as a possible “act of terrorism.” Defense Secretary Ashton Carter calls it a “senseless act of violence.” Navy Secretary Ray Mabus says the attacks were out of bounds: “While we expect our Sailors and Marines to go into harm's way, and they do so without hesitation, an attack at home, in our community, is insidious and unfathomable.”
Senseless? Unfathomable? Terrorism? I doubt it. If this incident was inspired by Islamic jihad, as many investigators suspect, then it probably wasn’t senseless. Nor was it terrorism. It was a rational, horrific act of war.
Americans think we’re tough because we have a strong military. In truth, most of us are soft. We know nothing of combat. We don’t regularly hear gunfire or worry about our kids dying in an airstrike. When somebody who’s angry at our government opens fire in one of our cities, we can’t believe crime has come to our own neighborhood. We call it terrorism.
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Are trainers and recruiters noncombatants? If so, we’re killing noncombatants every week. According to the Pentagon’s latest published data, our coalition in Syria and Iraq has struck more than 2,000 enemy “buildings” and nearly 500 “staging areas.” A “staging area” can be almost anything—according to the U.S. military glossary, it’s “a general locality established for the concentration of troop units.” Scan the Pentagon’s daily reports on the campaign, and you’ll see accounts of strikes against “barracks,” “compounds,” “structures,” “manufacturing workshops,” and “logistics hubs.” If you’re an ISIS foot soldier, it hardly matters where you are or what you’re doing. You’re a target.
Recruiters are standard fare. In February, we sent a drone to kill an ISIS recruiter in Afghanistan, even though, according to a Pentagon spokesman, the recruiter had “decided to swear allegiance to [ISIS] probably no more than a couple weeks ago. And he didn't have a whole lot of depth to any network resources or manpower when he did it.”
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http://www.slate.com/articles/news_and_politics/foreigners/2015/07/the_chattanooga_ killings_aren_t_terrorism_they_are_a_rational_horrific_act.html?wpsrc

What do you think? Does Mr. Saletan make some valid points?