OK, Anarchists, here's your big chance!

I am not going to directly answer the question, as the question has been set up on assumptions in a way that it would not happen. Transition would be more normal, it would take decades to transition.

But I think it is important to respond to the question of defense.
Iraq had a centralised defense
Eastern European countries during WW2 had a centralised defense
As well as many other countries, Japan, France, this is not a prerequisite for winning a war or defending a country.

The factors that usually determine a wars outcome are:
1) Size of enemy
2) Strength of enemy
3) Organisation of enemy
4) Propensity for enemy to attack.

The elements
1) Size of enemy, most countries are much smaller than the USA, so that rules out about 80% of countries that would attack.
2) The anarchic society would have a big weakness in that it would be less strong because of big ticket items would only be purchased by large groupings, Oil companies, Concerned citizens of Texas. So there would be less big ticket weapons, diminishing strength.
3) Lack of a central authority might exist, it depends on how sensible the society is.
4) So in an anarchic society, with no defense force, Canada would probably not attach as it is a friend. So that eliminates about 20% of countries that would attack.

If the society works on a charity army of mercenaries, there would be no issue useless everyone was happy to pay their share until the war started. :-)
But otherwise pacts would have to be made with other governments.

Realistically, only Russia and China could invade the USA in the scenario, so a lot depends on their attitude to the USA.

By the way, crime would be a part of an anarchistic society. There is no way to eliminate crime as long as people have free minds and conflicting goals.

http://www.youtube.com/watch?v=ehuMZjyA6z8

Anarchists have been asked this literally millions of times by nearly everyone they talk to, and I'm kind of tired of having to answer it every time. It's another one of those "but who will build the roads?" questions. Can't you go read some an intro to anarchy book and cover the basics without wasting more of our time?

Here, read this:
http://www.lulu.com/content/2935951

It includes a section on collective defense which answers your question.

It presents the tired Neoconic ideal that 'we go to fight them over there before they come here' which is just nonsense.

This is all completely divorced from reality because it doesn't take into account any likely scenario (Brazil invading, no one dare wronging their neighbor).

At it's best Anarchy is presented as an ideal to work towards and like most ideals things improve just by working towards them. Perhaps simply calling it the Ideal of Independent Freedom would be more suiting than Anarchism.

The best solution for a society are strong families woven into fruitful communities. That's really what it all comes down to.

============================

Glen Beck -- An Exposed Enemy:
http://www.dailypaul.com/node/90198
Glenn Beck Supports NAFTA and taking your job:
http://www.dailypaul.com/node/86643

If you experience any of these effects, you should seek the advice of a logician immediately.

It is you who needs the treatment of a logician stat.

Straw man:

A straw man argument is an informal fallacy based on misrepresentation of an opponent's position.

To "attack a straw man" is to create the illusion of having refuted a proposition by substituting a superficially similar proposition (the "straw man"), and refuting it, without ever having actually refuted the original position.

I prefer to ignore the absurdities of your hypothetical and look at the reality of how a free society would actually come to be - and how that would affecdt it ability to defend itself. BTW, there is no validity to your claim that only a government can provide military defense. Numerous authors have explained in detail why and how insurance companies would, for example, provide defense services.

Now, for reality. The achievement of a free society will occur, if at all, incrementally. It will have done so by means of the logic and power of its ideas which will have permeated the thinking of bulk of the citizenry. As human nature is universal, that is, all peoples share the ability to understand and desire the blessings of liberty and as we live in a highly interconnected world these ideas will, in this age of instant mass communication, have also spread dramatically throughout humanity. Accordingly, as these ideas gain dominance in the US they will have also greatly influenced the thinking of the people in the aggressor nations and this influence will work against the forces of aggression, creating enormous domestic dissent if the governments persisted in their aggressive ambitions.

Even absent the acceptance of a shared acceptance of the principles of liberty and rejection of coercion, the world's economic interdependence will only increase as a country of the US's stature makes clear and substantial moves towards liberty with all due haste. A freer US will have ever increasing and mutually beneficial economic ties with potential aggressor nations the benefits of which will create disincentives within those nations to attack a trading partner. Indeed, powerful forces in these other countires you wish to designate as hellbent on destroying the US will be a powerfu counter-force within those countries against waging a war of aggression against a free US.

Meanwhile, even as the US moves towards freedom, with the modern world's increased communications, it would become readily apparent early on that any aggressor nations were taking steps towards invasion. As the US at that point will have renounced interventionism and posed no invasive threat, the aggressor's warrantless militarism would arouse the entire world against them. They would lose access to bases, resources, intelligence and important commerce would be curtailed. They would be seen as moral pariahs.

Your hypothetical assumes without any basis that the instantaneous anarchist society will have dismantled its military. Considering the US spends roughly as much as the rest of the world combined on military expenditures these military assets are not just going to waste away. To the extent they have value people will make use of them. Much of the military hardware would likely be obtained by insurance companies. As mentioned before, insurance companies will charge a premium for providing defense services and it is highly likely they will have their analysts determine what threats exist towards their clients (the people in AWA) and what amount of military personnel and hardware are necessary to fend off attack. The cost of this service will be factored into client's cost of insurance coverage.

As an example of how the anarchist society could defend itself, Stefan Molyneux has pointed out that the first thing to note is that nuclear weapons have been the single most effective deterrent to invasion that has ever been invented. Not one single nuclear power has ever been invaded, or threatened with invasion – and so, in a very real sense, there is no bigger “bang for the buck” in terms of defense than a few well-placed nuclear weapons.If we assume that a million subscribers are willing to pay for a few nuclear weapons as a deterrent to invasion, and that those nuclear weapons cost about $30 million to purchase and maintain every
year, then we are talking about $30 a year per subscriber – or less than a dime a day. The defense agencies only make money if an invasion does not occur, just as health insurance companies only make money when you are not sick, but rather well.

marlow

How do you know this tread is not made just to get your responce for possible action in the future. Shut it. Rule of law , which law ? The ones that are no longer enforced ? ERGO your Justice System. ERGO your Presidency gets to choose which one the dept wants to enforce ...Ergo lazy Court. ETC, ETC.
Which ever way you choose to believe , YOU are on your own where the law is concerned .They choose which one to enforce...When they choose wrong , you know the results & so do they.
*They have to do it LEGALLY
Good people make the difference, you-no

The Anarchist Society vs. the Military State: The Insignificance of the Free Rider by Vedrun Vuk
http://mises.org/multimedia/mp3/Vuk.mp3

Outlines it completely... Guess who wins? :D