From my experience in SAC back during the Cold War circa 1975 we had numerous Operational Readiness Inspections testing out just such a scenario.
From the Time the Alert Klaxons sound and the entire base is on alert it will take at least 8 hours to break the weapons out of the igloos and load them on the individual bombers.But that was when we Had SAC a Unit that specialized in nuclear warfare preparations and attack.
This Global Strike command” Replacement of SAC” is not of the same quality and there personnel are not trained to meet the exceptionalism of SAC’s personnel.
I recently saw a video on youtube regarding a recent Alert and launch of the B-52 wing out of the 2nd Bomg Wing at Barksdale AFB,Louisianna.
That was the slowest alert and Launch of a wing that I have ever had the displeasure to see.
If that base was ever under an actual nuclear attack the entire wing of bombers would have been destroyed on the ground.
President Trump needs to return the use of Nuclear weapons to a specialized wing that has that job as there only Job. President Trump Reactivate SAC and deactivate the Global Strike Command.
If I remember during the days of SAC ground alerts, the weapons were already preloaded onto planes. By the 1980’s, you can see B-52G’s and H’s with AGM-86B cruise missiles pre-loaded on the wing pylons on ground alert.
1978-1982, GFAFB (if you have to ask, don’t) 321st Strategic Missile Wing.
The number of drills, inspections and run out the door at 0330 in the morning to stage out in the backwoods of North Dakota were epic. I have never been so cold in my life.
But they could get all of the B-52s in the air within 45 minutes (if memory doesn’t fail me).