The idea that anarchism must fail because under anarchy no one can make others obey the rules is stunningly stupid. On any given day, even in a world pervaded by states and their dictates, nearly everything that people do or refrain from doing is so not because the state threatens them with violence for acting otherwise, but because they find conformity with rules — honesty, promise keeping, careful handling of goods, avoidance of opportunism, and so forth — to be in their interest. The world does not run on the state’s threats of violence; it runs in spite of those threats.
Many sanctions besides violence and threats of violence may be — and are even in the world in which we now live — effective sanctions for adherence to law and order. Ostracization of dishonest dealers, for example, works wonders, and in the world of modern communications it can be more effective than ever.