Classical realism refers to an international relations theory that draws upon ancient traditions of political thought. Classical realist and neo-realist theories are primarily concerned with the world as it is as opposed to the desired state of things. In this regard, realism can rather be viewed as empirical than normative. Pessimism is another integral characteristic of these theories, which highlights the reoccurring patterns of politics, including conflicts, wars, and rivalries. The state is viewed as the central player when it comes to international affairs, while great powers are marked by having the most leverage on the global stage. While the classical realist theory highlights human nature and domestic factors, the neo-realist theory emphasizes the international system’s structure as a determinant of the state’s behavior.
Classical realism was developed as a response to utopian ideas of the interwar period and deals with the problem of balancing decisions with regard to pursuing power. In this view, realists consider states to have supreme power over their people, with a lack of a higher authority. Consequently, a system develops each country is concerned with its own interests first and foremost while becoming cautious about neighbors and their intentions. Ultimately, the classical realist theory highlights the world to be a place where everyone helps themselves. Military and economic power become the fundamental components of the state’s security and sovereignty. Political leaders build alliances and form armies to ensure national security. At the same time, the idea of a state’s aspiration to act in the best interest of the people constitutes one of the strengths of the classical realist theory.
In turn, neo-realism emphasizes the role of great powers in world politics and argues that the international political theory is based on this concept. The neo-realist theory differs from its classical counterpart in the root of international war and conflict, where neo-realists attribute it to the anarchic system rather than the imperfect human nature. In other words, the structure defines international relations and guides the actions and interests of states. The primary problem of this approach is constructing a scientific method to study international politics, as opposed to subjective evaluations of classical realism. Neo-realism relies on the international system structure of states and places states in a broader perspective which allows for seeing the structure’s advantages and disadvantages. Its systemic nature constitutes another strength of this theory, explaining the countries’ behavior and global impact.
As per the criteria of Bruce Bueno de Mesquita, in my opinion, neo-realism has more logical consistency as it seeks a structured and systemic perspective. This theory provides extensive discourse in international relations while applying its principles to international relations. Power is viewed as something beyond the wealth and resources required to gain control and superiority over other states. In this regard, the neo-realist theory treats anarchy differently; namely, the system is viewed as characterized by anarchy, and the power and capability of the country define its reaction to this phenomenon.
To conclude, the primary difference between the classical realist theory is the focus on human nature for the former and the international system’s structure for the latter. Addressing the problem of balancing power and security is the central problem in international relations. Historically, war was used to resolve this issue; however, as neo-realism has developed, the role of the system is emphasized rather than the turbulent human nature.