Why do realists describe the international system as anarchic?

In the study of international relations, realists describe the international system as anarchic because there is no central authority or suprastate power superior to individual nation-states.12

This condition of anarchy means that there is no global government capable of arbitrating disputes, enforcing international law, or providing a reliable guarantee of security for its members. Because no higher authority exists to protect them, states must operate in a self-help system where they are ultimately responsible for their own survival.12

Realists argue that this structural environment forces states to prioritize their own security and national interests, often leading to power-maximizing behavior and competition. Consequently, in the absence of an enforceable rule of law, war or the threat of war remains a primary means for states to resolve conflicts. While other schools of thought, such as liberal institutionalism, suggest that international institutions can mitigate or overcome this anarchy, realists maintain that such organizations lack independent coercive power and remain subject to the interests of major states.123