The article reads like it was put together by an aerospace conspiracy
theorist committee. It's got all the right buzzwords - reviving the
XB70 Valkyrie, plausible deniability, secret accounting practices, CIA
transport planes, boron-based rocket fuels, etc.

I'm inclined to point toward popular military SSTO and TSTO concepts in
the 1990s (e.g., Black Horse), which were simpler than possibly
airbreathing spacecraft launched from all-new or revived trisonic
mother ships, and used more mundane fuels (e.g., kerosene) than
boron-loaded pastes.

Then again, Lockheed's X33 was the bells-and-whistles, all-the-frills
ubertech approach to the SSTO that NASA picked over lower-risk options.
I wouldn't be surprised if the military was tricked into backing a
similarly over-complex alternative for a TSTO.