Is stealth dead?

A.J.P. Taylor observed that few of the commanders in World War I understood its real strategic dynamics as it was going on. Taught almost exclusively to understand attack -- attack, attack, attack -- the armies on both sides ground to a bloody deadlock when their rivals always proved stronger in defense. This mystified all sides, but the explanation was simple, Taylor wrote: The railroads meant defending armies could be reinforced and resupplied much faster than they were depleted by forces attacking on foot, through the mud -- simply put, defense was mechanized, but attack was not.

Fast forward to the 21st century. According to one school of thought, as the U.S. has spent billions of dollars on a relative handful of stealth attack aircraft, potential adversaries can spend millions on sensors and other technology to defeat them by detecting them. Like Taylor's defenders on the Western Front, the defenders have a theoretical advantage: With fixed ground stations, radar aerials can be as big as you want, consume as much energy as you need, and use as much computing power as required. An aircraft has to be able to fly, flight and maneuver, in addition to being stealthy.

Defense analyst Barry Watts takes up this debate in a new report published by his think tank, the Center for Strategic and Budgetary Assessments, and his thoughtful analysis provides an excellent, detailed primer for stealth skeptics:

In recent years there has been speculation that ongoing advances in radar detection and tracking will, in the near future, obviate the ability of all-aspect, low-observable (LO) aircraft such as the B-2, F-22, and F-35 Joint Strike Fighter (JSF) to survive inside denied airspace. Those taking this view emphasize at least two promising approaches to counter-LO, both of which are being pursued by the Russians, Czechs, and others.

One involves very high frequency (VHF) and ultra high frequency (UHF) radars, which use relatively long wavelengths of about 30 centimeters to six meters. The radar cross section (RCS) of an aircraft not only  varies with the wavelength of the radar trying to detect the plane, but the aircraft’s RCS is larger for long-wavelength search radars compared to its RCS as seen by the shorter, X-band radars typically used by SAMs for fire-control. Radar physics, therefore, argues that VHF and UHF search radars offer greater potential to detect and track stealthy aircraft.

He continues:

The other promising approach to counter LO has been passive systems such as the Czech VERA-E, which uses radar, television, cellular phone and other available signals of opportunity reflected off stealthy aircraft to find and track them. The main limitation of such systems has been the enormous signal-processing power and memory required to analyze all these emissions, differentiate real targets from ghost signals, noise and clutter, and keep the false alarm rate to manageable levels.

One potential outcome, however, is that as long-wave radars transition to AESAs (and assuming computational power continues to double every two years or so in accordance with Gordon Moore’s “law”), information acquisition will overwhelm the capacity of aerospace engineers to reduce platform signatures. The balance between information acquisition and information denial will swing dramatically in favor of the former. Or, to put the point more bluntly, there will come a time in the not-too-distant future when the SAMs will almost always win against air-breathing penetrating platforms, rendering operations inside denied airspace too costly to bear.

So does this mean game over for the stealth era? Actually, no, Watts argues. ("There are substantial reasons to doubt this conclusion," he writes.) It's worth reading his report to get his full explanation, but to sum it up, he says advanced new features on the F-35 will enable it to continue enjoying stealth advantages on tomorrow's battlefields: New electronic capabilities, the ability to attack in networked multi-ship groups, and others. This, of course, assumes they all work as advertised.

Watts also assumes tomorrow's defenders get full points for technological rigor, even though they have many technical hurdles to jump before they reach the point where they can see and kill every stealth aircraft.

What do you think?

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