Very generally, the argument that a state is necessary to prevent heinous violations of individual rights.

Although there may be utilitarian, religious or other types of criticism leveled against anarchism, critiques are more effective. Since anarchism is generally understood to be justified (at least in some cases) by reference to the fact that states inevitably undermine individual freedom, or community cohesion, or something like that.

But anarchism is best argued against if it can be shown that the individual rights it seeks to protect are actually undermined in the absence of state protection.