There is a paradigm shift that makes what was once true no longer true. Back when people were poor, unproductive, and technology was shit, the incentive to initiate violence to secure resources was higher than the incentive to defend resources (unless you were yourself a different force initiator). But today it's not like that. No violent gang on the planet is going to take over Silicon Valley or NYC. In the stateless hypothetical, the incentive for the vastly productive people to protect themselves would be far, far, far greater than the incentive to initiate violence against them to such a degree that they work for you. This is because the status of the productive people no longer has anything to do with initiation of violence and everything to do with protection of their property and environment.

This would be true even if today only the US went fully private. If taxes were zero and the military was traded on the stock exchange, we would still not see initiation of force from Russia or China because the primary incentive of the Chamber of Commerce and other non-affiliated major companies would be to contract their security from possible threats from Russia or China. I honestly think the contracted private military would get far more aggressive with bad actors than it is today. The goals of contracted defense companies would be far more clear and sophisticated than the current government and military.

It cannot be understated that capitalism flips the world on its head. For all history, things worked one way, but where capitalism has been adequately embraced, they do not. It used to be that the primary source of wealth was violence and control of others' production. It is no longer that way. Today the primary source of wealth is protection of property and commerce.