They don't all have to go along. See the "execution" section- only a couple of senior officers have to authenticate the President, and issue the order electronically. At that point only one chain between them and a launch crew have to obey the orders to launch. The whole process is meant to only take a few minutes.
Everyone involved in the chain is part of the Personnel Reliability Program. It's mostly to make sure someone doesn't launch without an order but also probably to make sure that they will follow orders, including launch orders.
https://en.wikipedia.org/wiki/Single_Integrated_Operational_...
Everyone involved in the chain is part of the Personnel Reliability Program. It's mostly to make sure someone doesn't launch without an order but also probably to make sure that they will follow orders, including launch orders.
https://en.wikipedia.org/wiki/Personnel_Reliability_Program?...