Probably billions.
Same goes with the Ukraine war. It too is an experiment. The Ukraine war didn't start because Russia & Putin decided they wanted to reconstitute the USSR. It's another instance of seeing how effective Mass Formation works with getting people to support war, as it also diverts attention away from what they see going on around them. In other words, their focus is diverted to the "aggression" of Russia. Furthermore, it serves with the goal of killing unwanted humanity while identifying those who are compliant & those who are not.
That is why I say the chains will be mental, not metal. In reality it is easier & more effective to have people control themselves than it is for them to do so. Those who show they cannot be controlled, will need to be dealt with in other ways.