"Technology must never advance for these people." is an unsustainable long term and even medium term strategy.
It's barbaric. And the actions needed to enforce it only raise tensions. And it won't work. Many nations that "must never" have bombs already have bombs.
The arrogance is bad. And it is not even arrogance informed by indomitable military power. Because there isn't enough power in the sun itself to keep a lid on this forever.