I stayed up late on the night of May 1 to hear President Obama's stunning announcement: A special-forces mission, which could have gone humiliatingly wrong, had instead succeeded in killing Osama bin Laden, the man behind the worst terrorist attack on American soil. I watched until the news reporters ran out of things to say, when they began to fill airtime by repeating things and asking the opinions of people in the streets while waiting for something else to happen.

I had to wait until the next morning to read more about how US forces had actually managed to achieve this victory, when I read this article in the National Journal online. The team of Navy SEALs that carried out the mission, I learned, were part of a special group of special-missions units and task forces known as the Joint Special Operations Command. The article went on to explain some more about JSOC, saying:

Recently, JSOC built a new Targeting and Analysis Center in Rosslyn, Va. Where the National Counterterrorism Center tends to focus on threats to the homeland, TAAC, whose existence was first disclosed by the Associated Press, focuses outward, on active "kinetic"—or lethal—counterterrorism missions abroad.

The definition of kinetic caught my eye. It was in quotation marks, followed by a gloss to explain its meaning. Apparently the author, Mark Ambinder, didn't expect his readers to be familiar with this specialized meaning of kinetic. But people have been getting familiar with it for several months now. My introduction to it was during the annual meeting of the American Dialect Society in January, when the term kinetic event won the "Most Euphemistic" category in the ADS's 2010 Word of the Year vote. A kinetic event is "a violent action in the field of battle," according to the definition Ben Zimmer is writing in the "Among the New Words" column in next month's issue of American Speech, the journal of the ADS. The term had been in the news from Afghanistan in reports like this one from September (to appear in Ben's entry):

The coalition is reporting ... that in August, just last month, there were more than 4,900 kinetic events. That's an attack, mortars, rockets, small arms, IEDs. (link)

In March, the public awareness of this new sense of kinetic was raised further by the phrase kinetic military action, the widely ridiculed term used by Ben Rhodes, the Deputy National Security Advisor in describing the United States' role in the ongoing conflict in Libya. Jonathan Allen wrote an article on Politico.com:

Police action, conflict, hostilities and now "kinetic military action." They're all euphemisms for that word that this White House and many before it have been so careful not to say: War.

Administration officials told congressional aides in a closed briefing earlier this week that the United States is not at war with Libya, and Deputy National Security Adviser Ben Rhodes danced around the question in a Wednesday exchange with reporters aboard Air Force One.

"I think what we are doing is enforcing a resolution that has a very clear set of goals, which is protecting the Libyan people, averting a humanitarian crisis, and setting up a no-fly zone," Rhodes said. "Obviously that involves kinetic military action, particularly on the front end. But again, the nature of our commitment is that we are not getting into an open-ended war, a land invasion in Libya."

Although the military sense of kinetic seeped into public consciousness in 2010 and 2011, as with many seemingly new words, it turns out to have spent a number of years paying its dues before getting its big break.

The euphemistic feel of kinetic comes from its association with scientific inquiry. Unless you're a teacher (who deals with visual, auditory, and kinesthetic learning styles) or an artist (who might create kinetic sculptures), the word kinetic probably brings to mind high-school physics class, and lectures about potential and kinetic energy. In fact, in its first uses relating to the military or national defense, kinetic did mean "relating to kinetic energy." In the 1978 edition of the Code Name Handbook: Aerospace Defense Technology the acronym SKEW is defined as a "shoulder-fired kinetic energy weapon". A kinetic-energy weapon, as opposed to a chemical-energy weapon, is one that does its damage with the simple kinetic energy of the projectiles it fires. A gun with ordinary, non-exploding bullets would be one example of a kinetic energy weapon.

Alternatively, a kinetic energy weapon could be a missile or other heavy object hurled from space, as long as it isn't equipped with, say, a nuclear warhead. A 1983 article in the Boston Globe quotes a brochure for a weapons conference as mentioning missiles as kinetic energy weapons. One part of Ronald Reagan's proposed Strategic Defense Initiative/"Star Wars" missile-defense system was the "kinetic kill vehicle" (KKV). The term starts appearing in news reports from 1985, and continues to do so even now, though these days the focus is more on destroying Chinese rather than Russian missiles or satellites.

A year after the proposal of SDI, the phrase kinetic energy penetrator as a synonym/euphemism for bullet was in circulation, and five years after that, it got a real workout during Operation Desert Storm, when US tanks were equipped with kinetic energy penetrators made of depleted uranium — a good conveyor of kinetic energy because of its high density. (I have to say, though, that using DU as a weapon by turning it into a really heavy piece of ammunition is like using a barometer to determine the height of a building by throwing it over the edge and timing how long it takes to hit the ground.)

These uses of kinetic seem to have paved the way toward its broader meaning of military attacks, which had become well-established by the time of the September 11 terrorist attacks. In a 2002 article in Slate, Timothy Noah introduces his readers to the term kinetic warfare:

"Retronym" is a word coined by Frank Mankiewicz, George McGovern's campaign director, to delineate previously unnecessary distinctions. Examples include "acoustic guitar," "analog watch," "natural turf," "two-parent family," and "offline publication." Bob Woodward's new book, Bush at War, introduces a new Washington retronym: "kinetic" warfare.

Noah then quotes from page 150 of Bush at War, in which President Bush and his advisors talk about "going kinetic" against al Qaeda after 9/11. Noah continues:

In common usage, "kinetic' is an adjective used to describe motion, but the Washington meaning derives from its secondary definition, "active, as opposed to latent." Dropping bombs and shooting bullets—you know, killing people—is kinetic. But the 21st-century military is exploring less violent and more high-tech means of warfare, such as messing electronically with the enemy's communications equipment or wiping out its bank accounts. These are "non-kinetic." ... Asked during a January [2002] talk at National Defense University whether "the transformed military of the future will shift emphasis somewhat from kinetic systems to cyber warfare," Donald Rumsfeld answered, "Yes!" (Rumsfeld uses the words "kinetic" and "non-kinetic" all the time.)

In addition to kinetic warfare and kinetic systems, there is a host of other 21st-century kinetic terms, including kinetic operations, kinetic capability, kinetic engagements, kinetic strike, kinetic activity, and kinetic targeting, i.e. bombing. These days the bombs don't have to be non-explosive; the opposite of kinetic targeting is soft targeting: dropping leaflets. Areas where fighting is going on are kinetic areas. Kinetic can be a predicate adjective, too, i.e., one that comes after a linking verb. An army unit might go kinetic, and an article from 2006 tells how British soldiers in Iraq believed their American counterparts were "too kinetic." (Kinetic Yankees, if you will.) There is even an adjective, post-kinetic, to describe reconstruction, or places where battles have taken place.

Commander Philip Thrash, an old high-school friend and former field artillery officer in the US Army, served in Aghanistan in 2007-2008. He confirms that it isn't just the top brass who use kinetic. He started to hear it among his superiors in 2003 or 2004, and during his service, he and his peers and subordinates used it often. As he explained: You hear your superiors use it, and if you want to communicate effectively with them, you use the words they use, and then it just becomes part of your lexicon. Kinetic is useful because it can cover a lot of more specific verbs, such as engage, acquire (a target), move to contact, destroy, neutralize. Summing up, Philip used an unsettling but soberingly accurate turn of phrase that has been in print since at least the late 1970s, and that some veterans remember from the Vietnam War. Basically, he said, kinetic is "a polite way of saying 'kill people and break things.'"