The stealth that we have now still ain't enough - and it will take a whole
lot of new stuff to deal. But like everything else and as I said before,
if you start targeting the SAM operators and their mothers they get a
quick change in attitude fast so we could asymmetrically, as they say, add
some diddles to the equation. It is perhaps then a "full spectrum" fight
(stealing from the Army)

The B-2, F-117, and F-22 already give a tremendous first day stealth
capability, especially with precision stand-off munitions. Enough to take
out any 3rd world and their SAMs. Especially given Weasel countermeasures.
As far as I know, SAMs are still highly allergic to anti-radiation missiles!
In my fictitious China/Russia scenario, there would be many more elements
besides airplanes targeting SAMs! UAVs, cruise missiles, special ops, etc.
Finally, Russian SAMs might be very good (who knows until they're used in
battle?), but I'm betting most of their for-sale operators aren't.

At the bigger picture, anyone using those weapons and seriously hurting the
US with them is going to prompt a US-Russia talk like the Britain-France
talk during the Falklands. Russia isn't going to want to trash US relations
over Kurzikstan or Somalia, so there goes their effectiveness (assuming that
US Intel doesn't already know about their capabilities and potential
counters). As Ed commented on my comments, I think the emphasis really
needs to be on winning the war of the media just as much (if not more so)
than the actual war. I believe that the US is on another generation of
operational capability compared to any other army in the world. I'd bet good
money that the US could sit idle for the next 30 years and still be on par
with anything coming out of Russia or China with the current arsenal. But
they don't want to be on par, or just win wars, they want (i.e., the public)
to win wars faster, cleaner, and easier than ever! It's the media, and
public perception, that are (and have been since the end of WW2, and
especially the end of the Cold War) the limiting factors on US military
success. So the trick becomes how to best prosecute a war that pleases the
public? Make it as humane, bloodless, and fast as possible. That, IMO, is
the biggest strategic reason for pushing technology forward. Not enemy
weapon/defense developments. Even if all other countries ceased developing
weapons, and went back to using spears and rocks, this reason alone would
still drive US weapons development just as much as it is being driven now
IMO.