What if it's not about making the enemy believe in aliens, but making the enemy believe there is technology available that is "other worldly" advanced. Basically a psyop.
No such adversary would likely believe the claim that the US has suddenly developed physics-defying technology thousands of years ahead of what should even be feasible, which they just recently decided to leak like a sieve about. And the only thing the US does with this technology is troll their own military.
If it is a psyop, it's a stupid and obvious one.
https://www.vice.com/en/article/n7wjzg/the-skeptics-guide-to...