Under the current aircraft protection rules, the containment building has to survive impact of a fully loaded large civilian airplane moving at speed of sound.
For example testing of samples of containment building was done using acceleration of F-4 Phantom mounted on rocket sledge towards the wall. The wall survived the impact without problems.
Which already exists. For example, India (so that you cannot say "this is something only available to USA) has the Agni-V (https://en.wikipedia.org/wiki/Agni-V) that supports a 7.5 ton bunker buster with Mach 24 terminal velocity. It costs $5 million each (like a battle tank).
Your squishy 747 moving at Mach 1 is nothing in comparison.
What other countries do already have something similar, or will have something similar, let's say, in the next 5 years?
https://en.wikipedia.org/wiki/Dnieper_Hydroelectric_Station#...