The author of the paper has no real knowledge. The Minuteman system, for example, has redundant cables running through pressurized pipes buried underground, as well as other detection and rerouting capabilities.
This paper shows a significant misunderstanding of the command and control structure and procedures at STRATCOM (formerly SAC), National Command Authority (NCA) and other key elements of the process. I am waiting for the author to explain how the attacker will obtain the encryption codes to MILSTAR, SLFCS or any of the other communication channels into a Minuteman Launch Control Facility or the equivalent communication channels going to bomber squadrons, submarines and other force components with nuclear capability. Then there are enable codes, launch codes and various other keys that would be needed. The article also fails to address safeguards in place. One needs to only examine the "incidents" that have occurred in real life, such as a exercise tape accidentally being loaded at SAC, prompting incoming ICBM warnings, to see that these procedures worked even 20 or 30 years ago, and they hve only been improved since then.
Having worked on the unauthorized launch studies for Peacekeeper (the decommissioned ICBM system often referred as MX), I can tell you the author did not have the data needed to be able to conduct this study, much less draw any valid conclusions