Even anarchy requires consensus... even if it is a consensus to allow members to act counter to the group's intentions. Either way, anarchy only works when individual actions do not dangerously impact the whole. When they do, and they must be reined in, anarchy is over.

Our present political systems are relatively simple, based as they are either on family dynamics or group dynamics; and both of those dynamics are based on social systems that evolved on this planet (with multiple species) to support survival. Since, as I suggested before, another race may have evolved under very different social or physical pressures, they would have likely evolved different social dynamics, and their politics (if they had any) would likely have been influenced by those social systems.

This doesn't necessarily mean they would be more complex, but they could emphasize different aspects of group dynamics than we are used to (decisions could be heavily influenced by time passed, or argument weight could be impacted by health, etc). So we could see more complex political systems, or simply more incomprehensible systems.

I hate to disagree with Clausewitz, but I don't see war as the continuation of politics by other means... unless you see organized and premeditated murder as a legitimate political tactic (I know some political groups do see it that way, but I don't). As politics and social systems are about Agreement, and murder is about as far from agreeing as you can get, war has nothing to do with politics; war is what we resort to when politics breaks down; it is a refusal to cooperate. War is about usurping another's fundamental right to their life.