Not really weighing in on Mr. Hallyer's assertions, but just to suggest from an astronomer/engineering perspective:
There are a great many advantages to constructing a military outpost on the moon (though a better idea would be to construct at least two bases, one
in each hemisphere to have 24/7 360-degree scanning capabilities).
One advantage would be the ability to monitor the near-space vacuum with much greater resolution and operational efficiency and with far less
interference from such things as radio noise, atmospheric obstructions, political enemies and a nosy public, etc.
Another great advantage would be the ability to detect and identify any anomalous activity at a greater relative distance such that time to weigh and
act upon a response strategy is maximized. At ~224,000 thousand miles, the distance between the earth and the moon is just a tiny fraction of the
space between other celestial objects in the solar system. The average distance to the sun, at 93 million miles (150 million kilometers) by
comparison is immensely greater and is still just a relatively short distance relative to the outer planets. Therefore, a base on the moon is not
much different than a base on earth would be when considering distances in the solar system.
Perhaps the greatest advantage would be the far lower cost of maintaining a defensive posture from one or more outposts on the moon than on earth.
The engineering and, (consequently then, of course) practical expense of forcing tiny payloads through the earth's atmosphere and strong
gravitational pull are exorbitant. It would be like trying to attack Godzilla with spitballs and rubber bands. You simply can't effectively,
quickly, or numerically succeed by dragging millions of gallons of liquid propellant out to a launch pad over several weeks or months (if you're good
and you're lucky and you're very wealthy), hoist a little peeshooter on the top and then expect to "win" anything. What if there is more than one
or two incoming hostiles? What if there are dozens, or hundreds?
The moon allows for rapid deployment of small, nimble, easily constructed, easily maintained, efficiently equipped defensive craft and their support
structure. Yes, it will be (is?) ridiculously expensive to build.
But once completed, the ability to monitor from great distances and take potential action against any threat is magnified tremendously.
Keep in mind that there may be "other" peripheral uses for such a base: scientific research, asteroid monitoring/defense, exploration, resource
extraction just to name a few...
OK, enough for now - just my opinion. Interesting video, though I agree with some that the validity of the source is honorable perhaps, but not yet
verifiable. And I get the impression that Mr. Hellyer has his own agenda - which may also be of noble intent. Not sure - just saying...
Anyway - thanks for the thought experiment if nothing else...