http://mises.org/journals/scholar/Hoppe.pdf National Defense starts on page 14.

http://daviddfriedman.com/The_Machinery_of_Freedom_.pdf Click on National Defense in Part III of the Contents.

Here is a good list of links that cover a lot of Anarchis subjects. I like the stuff from Lysander Spooner stuff.

http://praxeology.net/anarcres.htm

Historically, it has sometimes worked very well indeed, e.g. for the Ottomans for centuries.

“We can say with confidence that practical solutions would arise in an anarchistic society, though, because there would be no tax funding to shift the costs of warfare onto people who don’t make the decision to go to war”.

No, for the simple reason that the old “raid and trade” approach would work, under which people do whichever turns out more convenient. It doesn’t take taxes to shift costs that way.

The current formula for conquest is to invade an area then set up a puppet government made up of local people that are controlled by the invader. Most of the population will follow this new government because following government is all they know.

Even in today's world this type of conquest is not working well. Look at the situations in Iraq and Afghanistan. A very small minority of the population is opposing the puppet governments and their masters and this is causing huge problems for the invaders. Now think of what it would be like if most of the population did not believe in any government. Add to this the fact that a large portion of the population would most likely be armed in a stateless society. You can see that they would be nearly impossible to conquer a stateless society of any considerable size.

These dynamics were played out historically in the case of the English conquest of Ireland. The Irish people did not live in the same type of feudal society that English and most of the rest of Europe did. They had leaders that were elected from certain families that were their combat and spiritual leaders, but individuals were free to change leaders without moving and often did. When the English invaded with vastly superior numbers and technology they won the battles, but found that they could not rule the people. The English would defeat a local leader and have them sign a treaty. They would then install one of their own noblemen as the new Lord, but as soon as enough soldiers marched off to fight in a new area the locals would rise up and over through the new government and cause the English to have to start all over again. This went on for close to 400 years. With modern weapons, technology and media coverage, that type of long drawn out conquest could not be sustained.

As far as "Anarchists will need to think through some larger scale mutual interest issues", I assure you that just about every large and small scale issue has been thought through. Anarchism has been around for a long time and countless books, articles and web postings and debates have been written. I am not saying all anarchists agree, but there has been a lot of thought put into it. I am sure if you do little research you will find plenty to read about.

In a stateless society you would be free to intervene in a conflict or not as you choose. This could be personally by choosing to fight or through financial support. You could even hire someone to go and fight if you wanted and had the means. Distance has nothing to do with it. It would not matter if the people being attacked were next door or half way around the world. The idea that the people in an arbitrary geographic region are tied to each other more than any other people is a statist one.

In today’s society you are forced to support whatever military actions your government endorses and forbidden from supporting the ones that they don't. It is all about freedom or the lack of it.

Hope this helps.