Some commentators will look at the Russian brochures, note that the reference ranges are against targets with an RCS of one square meter and observe that stealth aircraft have a far smaller RCS, which they do—in centimetric bands. Giving what was probably the least provocative answer under the circumstances, a Russian engineer notes that the Chinese DF-15 short-range ballistic missile has a 0.002 m2 RCS in X-band, but is a very non-stealthy 0.6 m2 in VHF.
Two exhibitors at MAKS were showing passive RF tracking systems. They are intended to exploit active emissions from the target but do not discriminate. Scattered energy from a radar will work just as well. The U.S. Air Force does have a modern facility for testing such bistatic radar signatures, but it was commissioned after the JSF was designed.
The Russian approach has its weaknesses. An Aegis on wheels makes a valuable, conspicuous and soft target when working. The claimed 15-min. set-up and strike-down time is ambitious, and the system has to have a fighter-like price tag. There is also no reason that a low-RCS target can’t use jamming, either onboard or offboard.
It would be reassuring to know that the stealth technology upon which the Pentagon plans to base air dominance for the next few decades has been thoroughly, recently and aggressively Red-Teamed against multiband AESAs and passive systems. If it has, nothing has been said about it.
There may be a universe where it is smart to give your adversaries (or their armorer) 25 years’ notice of exactly how you plan to render their defenses obsolete. We just don’t live there.