(Having problems with the browser, can't post on comments, so I thought I'd post here.)
These discussions about "anarchism doesn't work" amuse me. They tend to be very belief-based. The concept is, that if a system is not overthrown up until this minute (read: "if life is not eternal"), it is meaningless/a failure. If a marriage ends in divorce, it was a failure. But if a couple beats the shit out of each other until one of them dies, it was a successful marriage. Congratulations, widow, your relationship wins.
So if a community has a good thing going, lasts for x number of years, and some bastards shoot them, well, "the system can't work." That's because of the basic belief of the evil of human beings.
You could say the same of ANY system. Eventually, someone kills everyone. So they ALL fail. Leading me to think of anarchy as the default. If anarchy "doesn't work" because people are evil, NOTHING works for the same reason.
Whether you refuse to consider the basic necessity for society (hence the basic NON-evil of humanity), it's irrelevant. It's useless to consider who "wins" in "the end." (The end of what?) It makes sense to actually consider the morality of the situation and whether individuals and societies should allow each other self determination, or whether you sink into the mire that is "might makes right."