Even if you are under threat, what purpose is served in the modern age by putting bombers on alert? The war would be over before they reached an interesting target.
As I am sure you are aware, there is quite a bit of solid policy discussion on the various nuclear engagement scenarios. For this particular question the idea that if you can respond after a pre-emptive first strike then your enemy will have killed themselves by killing you. Since self preservation is a common thing, the ability to respond post initial strike is essential.
Seriously, I really do think it is instructive to read the literature on this. Missiles in silos are counter balanced by a premptive strike on the silos, mobile missiles (like the MX) are pre-emptible as well but need more warheads, subs are a good counter threat but are tracked by other subs, and nuclear depth charges are able to clear lots of ocean fairly quickly, bombers with cruise missiles are countered with aircraft.
In all cases there are costs and visibility challenges like you have to open your silo doors before you shoot missiles and over the arctic missiles take 30 minutes to arrive. Bombers in the air can see fighters who might be tailing them but they cant be countered by ground based missiles easily, it literally goes on and on. Measure, counter-measure. Signal, counter signal. Threat, defensive capability.
Literally end of the world as we know it kind of stuff so a lot of time and effort has been invested in understanding it.
I've read a lot about it, and I just don't see the purpose of having bombers on alert these days. It seems like their capabilities are similar to those of ICBMs as an alert force, but worse in every way. They take longer to launch, they're easier to destroy, they're vulnerable for longer, they take longer to arrive, and they are much easier to intercept on the way.
Rather than lecturing me on how I should read more and question less, maybe you could tell me just what advantages bombers have over missiles as at alert force?
Excellent, it is safer to assume people haven't read up on the science and policy behind nuclear deterrence so I generally err on the side of caution. Given that ...
The discussion about putting the bombers back on alert is driven by discussions to not renew New START[1]. As you know the air 'leg' of the nuclear trident counters the simultaneous elimination of the the strategic missile forces and the submarine forces by an adversary. One can estimate the number of warheads necessary for that to occur, and while we stay under the lower limit of that estimate there is surety that the bombers would be superfluous. In the event that New START does not renew (2021) or it is pulled out of early, it takes a while to recover the strategic bomber fleet to full readiness status. Training, people, etc. Some of that can be 'short circuited' by pulling retired (but still trained) individuals back into active duty.
You also know that SAC air bases are located such that they can launch (when they are on alert) in less time than it takes for a submarine launched cruise missile to get there and destroy the base. Those bombers would have the capability to destroy our likely adversary. Further you can launch bombers in DEFCON 2 in anticipation of an action which signals your readiness to fight without committing to wholesale destruction of the planet.
You also know that the threats that stand between the bombers and their targets have counters in place to insure that their mission (the destruction of the adversary that just killed off the US) would likely be successful.
They are, and pretty much always have been, the "revenge" team.
What kind of attack could take out ICBMs but would be unable to take out bombers? You say that bombers on alert could launch in less time than it takes for an incoming weapon to destroy the base, but surely the same is true of ICBMs.
Adding bomber bases to the list of targets the enemy must destroy makes their life more difficult, but it seems like the difference would be small. There are, what, half a dozen or so bomber bases you'd have to destroy? One warhead each should do it. My understanding is that ICBM silos are sturdy enough to require a nearly direct hit to destroy them, so you'd need hundreds of warheads to destroy those.
The ability to launch bombers and then change (or cancel) their mission en route is super useful, but that seems separate from the alert role. If you want to put nuclear bombers in the air to put the fear of God into your adversary, you don't need them to be on a five-minute alert (or whatever the actual time will be).
Nothing to do with START. It's all about the NK war. Do you also believe the story that they recalled 1000 retired pilots due to shortages in recruiting?
And that this weeks evacuation "drill" was already scheduled?
The only situation I can think of bombers like the B-52 (non deep strike bombers) being practical is against an enemy without serious air defenses. Think Syria, Iran, North Korea, etc... Perhaps as a retaliatory strike against non conventional attacks with WMDs like chemical and nuclear attacks via container ships and terrorism.
The B-52s don't carry bombs anymore, they carry cruise missiles. They drop off eight of em about 1000 miles from the target and turn around. It is still very questionable whether the AGM-86 is viable penetrating Russian airspace, but at least they have eight times as many targets to deal with.
... Unless the silos are attacked by Submarine launched ballistic missiles using depressed trajectories as part of a neutralising/decapitation first strike.
See it's the complicated, many possible options, nature of war planning that makes stuff like this much less black and white.
Whose submarines are you thinking of that could destroy all of the US ground-based missile launch facilities in a first strike?
The war planning based around what you describe assumed the Soviet submarine fleet, yes?
Are you worried about Russia, China ("the Type 094s noisiness would make it difficult for it to reach and maintain patrol areas where it could strike at the contiguous United States"), or India?