Now you see it...

ALTHOUGH BEAUTIFUL BY few standards, the F-117 Nighthawk -- the Air Force's black, angular, "Stealth" fighter -- looked like the future when it was unveiled in 1988.

Sculpted to evade radar, the plane -- despite its name it's really a precision bomber, or "strike" plane, not an air-to-air fighter -- became a star of the first Gulf War, flying some 1,300 sorties, and it got the call for some of the most sensitive missions of the second Iraq war, too. In 1999, it helped drive the Serbs out of Kosovo, though not before a Serbian anti-aircraft missile managed to knock one out of the sky. The pilot ejected, and was safely plucked out of enemy territory, but that one of these superplanes was laid low made news around the world.

To hear its fans tell it, the F-117's place in aviation history is secure. "It moved stealth technology to the fore for the Air Force," says Lloyd W. Newton, a retired four-star general who flew F-117's while leading an air wing at Holloman Air Force Base in New Mexico in the early 1990s. "You could take this plane right into the jaws of the enemy, without worrying that you were going to be picked up."

Nevertheless, all 55 current Stealth fighters will be retired by September 2008, a surprising turn of events for those old enough to remember the F-117's splashy debut. (Twenty larger B-2 Stealth bombers, cousins of the F-117 that became operational in 1993 and that bear a family resemblance, will continue to fly.) Given that the Air Force continues to rely on such earlier-generation planes as the F-15 fighter (first flight: 1972), the B-52 bomber (1954), and the slow, ungainly, but bullet-resistant A-10 "Warthog" (1975) -- albeit with lots of new technology stuffed into them -- it may seem puzzling that the once-cutting-edge F-117 is already being mothballed.

The Air Force stresses that the F-117 is older than it seems, since it first flew in 1981, seven years before the public became aware of it. Still, the retirement of one of the most celebrated military planes of the last two decades of the 20th century underscores the strategic and financial balancing acts the Air Force must perform as it tries to gauge what future enemies of the United States will look like.

Unsurprisingly, the Pentagon's last Quadrennial Defense Review, in 2006, affirmed that "irregular" combat, against low-tech armies or insurgents, would be the "dominant form of warfare" for the near term. In those conflicts, low-tech and sturdy -- like the A-10 Warthog (designed to circle battlefields slowly, take fire, and protect troops) or the lumbering AC-130 gunship (deployed recently against suspected Al Qaeda terrorists in Somalia) -- can be more effective than the leading-edge planes that define the Air Force to the world, and perhaps to itself.

Critics often charge that the Air Force is biased toward the high-tech planes, as opposed to workhorse machines that directly support ground troops. That's why there was an outcry in 2003, when the Pentagon proposed grounding the A-10 to save money. (Under the same plan, the F-117 would have flown for at least another decade). After vocal protests on behalf of "the Hog that saves the grunts," that plane was saved, meaning cuts had to be found elsewhere.

At least for now, says Robert Coram, the biographer of John Boyd, a leading air-power strategist who died in 1997, "the Hog and the AC-130 rule, and that must cause a lot of heartburn among the four-stars."

But there's another side to the story. Some Air Force leaders worry that Pentagon planners, understandably attuned to Iraq, are too single-mindedly focused on low-tech insurgencies. At a meeting of the Defense Writers Group, in Washington, D.C., in November, General Ronald E. Keys, head of the Air Force's air combat command at Langley Air Force Base, stressed that the defense of Taiwan, or South Korea, or conflict with Iran, would require far more sophisticated equipment than the conflict in Iraq, which often involves "trying to find one white SUV racing down the road."

And high-tech in the Air Force today means the F-22 and the F-35. The first of the new F-22 fighters, which cost $135 million each, joined the force in 2005. Like the F-117, the F-22 is stealthy, but unlike it, the F-22 is also supersonic and highly maneuverable -- it's dogfight-ready. The Air Force had wanted 380, but Donald Rumsfeld limited them to 183. The Air Force is also finishing testing on the F-35, another stealthy fighter, which is slightly less capable but is also less expensive ($40 to $65 million apiece) and will be purchased in much greater numbers. (The F-35 is viewed as the replacement of the A-10, which will ultimately be phased out, as well as of older fighters like the F-16.)

As a second-best high-tech plane, the F-117 suddenly became vulnerable, caught between the high-tech and lower-tech prongs of strategic planning. "There is no mission where you'd rather have an F-117 than an F-22," says Rebecca Grant, president of Iris Independent Research, a defense-consulting firm. Killing the F-117 will save $200 million annually in flying and maintenance costs.

One pressing problem that won't really be addressed by the Stealth fighter's retirement, because it's not a particularly old plane, is the ever-rising average age of Air Force aircraft. In the Vietnam era, the typical plane was 8.5 years old, according to the service's public affairs office, while today it's at an ominous 24 years and climbing.

The F-117 has its fans within the Air Force, and it has its place not just in military but also in cultural history. (This is the plane that helped give birth to such terms as "stealth advertising," after all.) But thanks to financial and strategic pressures, it will soon be flying -- presumably undetected -- into the sunset.

Christopher Shea's column appears biweekly in Ideas. E-mail critical.faculties@verizon.net.