1. Would B-2 Bombers go at it alone? Depends on a mission, i guess, but now with f-22 being in full service, it is quite possible, if not probable, most dangerous B-2 sorties would be accompanied by f22s for protection. We don't know any official figures, but lets say B2 offers less of a signature - all that would mean is the F22s would have to trail it some 30, 50 or so kms. Such a distance could be covered in tens of seconds if needed, so F22s could engage the interceptors.
2. More planes means more chances for detection. That is one of the things to consider when thinking about sending 1 or 2 B2s, with fighter cover or no fighter cover, with jammers behind them or no jammers, etc. Truth is, when we're talking about deep strikes, not just waltzing to the first line of enemy defence and surveillance systems but going over them, deeper into enemy territory - sporradic signals are a given. Depending on number and position of radar systems defense has, they are bound to get short blips on their screens as stealth planes pass them by. Signal strength will also inevitably vary, as the surfaces on the planes move, and even the plane itself, when moving, like banking or something, may add a bit more of signal to certain radars. So, against an enemy with wide enough network of radars - there will be no complete surprise. They will know 'something' is out there, and they will know the approximate trajectory. But, as we said, that something needs to be indentified, one needs to make sure its a B2 and not some kind of other stealthy drone and decoy. But the bigger problem is with engaging such targets. Radar guided SAMs would be mostly ineffective, unless the target is really close. So all that the defense would have is sending planes to search for the target.
3. Searching for a b2 in a dark of the night is hard, but not AS hard as some claims on this thread. Depending on coordination and communication between the search planes, their numbers and the IRST systems they'd rely on - a dozen of them could cover pretty much whole of vertical space while covering a 40-50 or so km wide horizontal area. More planes, naturally, could cover more. Eyeballs would not mean much in such a search, unless b2 commanders are desperate enough to fly a sortie on a moonlight lit night without much cloud cover. Even that way, an IRST would be more efficient than an eyeball. Some people will always claim 'but b2 and f22 dont emit heat', just like some will say 'they dont show up on radar' but that's false. Just like with radar, IR stealth only means reduction in detection range. Luckily for defenders, due to the fact heat can not be contained and must always escape somwhere, reduction is proportionally less than in radar. 5km detection range i used here is really ridiculously low, and in real world it would easely be more, but it was to prove a point.
4. But, it all brings us back to point number one. There would likely be fighter cover, and the interceptors searching for the b2 would likely be engaged before finding anything. Yes, f22s would most likely have a higher IR signature than a b2, but not enough to make much of a difference. In the end it would come down to number and quality of interceptors against number and quality of fighter cover planes. At best, defender might hope for a pyrrhic victory, forcing the fighter cover to flee when they run out of ammo and leaving the b2 unprotected as it also starts to flee but, due to its speed, that could easely mean its death. So, a b2 is downed, some might say that's quite a success... but if for such a 'victory' a loss of 50 or 60 or more advanced fighters is needed - i'm not sure there's a country in the world that could afford it.
5. Raptors have shorter legs than a b2. So, naturally, attacker might not be able to attack wherever he wants, but only to the point he can offer its b2 fighter cover.
6. Alternatively to this all - attacker might not pursue deep strikes at all, but be content with peeling the outer layers of defense and surveillance network, one layer at a time. It would take much more time, which sometimes in a war is a luxury, but if there IS time, it certainly is a less costly proposition.
7. Making stealth models without operating stealth planes is certainly not AS wild as it was suggested here. Problem with operating stealt planes is not designing them to have a low RCS, to an extent its not to make up a material that will absorb EM waves, the problem is to adapt those technologies to a plane that has, in additon to being stealthy, to do loads of other things. So, while operating a stealth bomber or fighter is mightly hard, measuring the RCS and IR signatures of models designed solely for such simulation is relatively speaking far easier.
