I don't see what the connection would be here. I'm not concerned about private armies overthrowing big capital. In the ridiculous notion that we have an ancap world, what I'm saying is that big capital colluding with each other and organizing private armies would be little different than the current capitalism we have today--except what was once public becomes private. I don't think the NAP would make a shred of difference any more than the constitution does today.
I take it you believe Big Capital is effectively in charge today. Clearly, it isn't the army that is in charge of the US (unlike some other countries).
Why is it, in your mind, that the army isn't taking over from Big Capital
today? After all, the army has all the guns, and by your dismissal of the Constitution, it isn't that document that stops them either.
What is it that stops the military from taking over from Big Capital (or just civilian government)?
I don't see how this would be accepted. Society does not operate by principles alone and they come together as a result of common interests (and private property is NOT one of them).
What are the common interests based on which today's American society has come together to virtually universally accept the Constitution as the fundamental principle based on which force may legitimately be used?
If the NAP (which makes every person a sovereign over his own body and peaceful projects) isn't a principle over which we can all agree, why would the Constitution, a convoluted, highly complicated and easily hijacked mechanism for determining which uses of force are legitimate, be one?
What I think is striking, which you don't seem to take into account, is how easily the constitution can be violated or any of our "moral principles" (such as love thy neighbor), by the power elite and there is nothing that we can do about it unless we unite against it.
What makes you think I don't take that into account? I view the Constitution as a well-intentioned, highly-flawed and greatly-abused document. Having said that, there is no doubt that virtually all Americans support it. Why do you suppose that is the case?
And if that is the case, why do you suppose it impossible or improbable that most Americans won't support the NAP in a similar capacity?
In your ancap world, I simple don't see why the principle of the NAP will make any more difference than any of our current principles now, or the constitution. Those who have power will do what they can to keep it--and even use your precious principles, like the NAP, to justify what they do.
You have posed to separate questions. One, why would those with the most resources in an ancap society bother protecting the NAP, rather than abusing it? My answer is by analogy - those with the most guns in our society do protect the Constitution, also a piece of paper (or a set of ideas and principles). As long as a principle is widely accepted (the Constitution in our society, the NAP in an ancap one), society can effectively ensure its respect.
The second question regards the likely consequences of an NAP-governed society (and, by extension, the likelihood that it would enjoy broad support in a hypothetical world in which most people are motivated by self-interest rather than principle).
This is a separate question we have explored at length. In a nutshell, and assuming the NAP (and, by extension, property) are well-protected, moneyed elites lack the tools (today available through government) to prevent their own usurpation.
As a very simple example, please consider the following question (which I posed before, but I don't recall you answering):
How could a capitalist-controlled factory compete for workers with a worker-run syndicate? Since workers are much more likely, by your logic, to prefer working for a syndicate, and since in an NAP-respecting society nobody can stop them from so doing, why wouldn't you expect capitalist enterprises to die a quick death as their workers abandon them on-mass to work for competing syndicates?
Free men are not equal and equal men are not free.
Government is not the solution. Government is the problem.