Technically I don't believe any radar can detect a VLO aircraft like B-21 300km(or even 200km) away. If you check the map, you will find this range is way off for interrupting bombers crossing 1st island chain. Let alone the fact that all anti-stealthy radars are very expensive and bulky, so it's hard to deploy them in a random small island but only few islands are ideal.
AEW aircraft, shipborne radar, land based radar, with modern networking, I believe can substantially increase the ability to detect VLO bombers especially if you operate in a region where you know the VLO bombers have to fly through.
AEW aircrafts and ships are much better, but just like land based radar, they are expensive, insufficient to defend the whole 1st island chain. Considering the existence of fighters and AShBM, it's also difficult to deploy them around 1st island chain before the first day.
They are capable of being deployed during the first day, because China will not start shooting at them prior to commencement of hostilities.
much less, given the budget of B-21, SSN and NGAD. BMD is basically the only important project in around 2015 but for now they are focusing on future attacking platforms.
That is partially because offense outweighs defense in the US strategic doctrine and plays into their pre-existing geographical advantages. Partly it is because those projects (new bomber, new SSN, new generation fighter) are the ones where the US has been needing to move onto the next generation anyhow.
But comprehensive BMD development and procurement remain ongoing, with current projects underway either in development or construction (Flight III Burke, new SM-6 and SM-3 variants, new THAAD variants).
that's based on timeline of Aegis test, while practical updating is even later. But anyway, even 500 missiles is more than enough to overwhelm the whole 1st island chain.
Why do you need to segment your air wings to 4 aircrafts/group if you believe you can defend missile attacks? That's what USAF is doing in 1st island chain.
Because you want to be able to defend against the missile attack while also maximizing the survivability of your aircraft to give yourself every advantage, in case if some of the missiles get through or if the enemy launches a larger salvo than expected, you do not lose everything due to an unforced error.
One of the prior tasks of B-21 is hunting for TELs and SAMs in the first day(of course, with bombs rather than stand off missiles). There's one more order of magnitude of difficulty than penetrating 1st island chain.
I'm aware of the USAF's demands for the aircraft. Depending on the opfor nation, depending on the theater of the opfor nation in which the B-21 is operating, it may well be possible that they can do day one hunting for TELs.
Against the PLA, in the 2030s, in the ETC or STC? Much more doubtful.
do you know how large the area between 1st island chain and Guam is? a 10km wide path is enough for penetrating but you have to monitor 4000km for interrupting. If you don't know how difficult it is, you can try it with CMO or any other simulators.
Again, you can test it with CMO. even with their terrible database, this amount is far more than enough.
CMO is a fine tool, and while its modelling is fine, it relies on the data to be accurate, which it seldom is.
I never said that the US needs to saturate the entire area with AEW&C and Aegis ships to pose a threat that is able to credibly degrade H-20 strike packages to Guam.
Even without missile attack and LO capability, any contemporary SEAD operations can easily create multi holes in an IADS. Don't overestimate air defense, they are searchlights in heavy fog, not a wall.
I am aware.
Carrying out SEAD operations against US integrated IADS in the first island chain to second island chain region (comprising land based aircraft and radars, at least 2-3 CSGs, and multiple additional SAGs with aegis), I believe will be very difficult.