International relations as a field of study emerged after 1919, focusing on theories like 'idealism' and 'realism'. Post-1945, economic globalization became a key aspect of analysis. John H. Herz and Kenneth Waltz were influential in developing neorealism, which looks at power politics between states on a global scale. Waltz emphasized the importance of power distribution in shaping international relations, discussing different power structures like unipolar, bipolar, and multipolar systems. Neorealism has evolved since the late 20th century to adapt to changing global dynamics.