Passage Summary: Laws only really work if there is someone like the police to enforce them; since the world doesn't have a global police force, international laws aren't actually effective.

Conclusion: International law does not qualify as effective law.

Reasoning: Effective law requires an enforcement mechanism like a police force, but there is currently no international police force in existence.

Analysis: The author is operating under a very 'might makes right' philosophy here, assuming that a police force is the only way to achieve effective enforcement. To find the necessary assumption, we need to bridge the gap between the lack of a 'police force' and the lack of 'effective enforcement.' The argument falls apart if there are other ways to enforce international rules, such as economic sanctions or diplomatic pressure. Look for an answer choice that confirms a police force is the only possible mechanism for making a law effective.