What serves as an intellectual tool to organize and understand the complexity of international relations?

The correct answer highlights the importance of theory in the study of international relations. Theories provide a systematic way to understand complex phenomena by offering a set of principles or propositions that explain how different elements within international relations interact. They help scholars and practitioners to make sense of various global issues, predict outcomes, and guide policy decisions.

In the field of international relations, theories can cover a wide range of perspectives, including realism, liberalism, constructivism, and more. Each of these theories offers different insights and interpretations of state behavior, power dynamics, and the role of non-state actors, allowing for a more nuanced understanding of global affairs.

In contrast, while frameworks, models, and hypotheses can also aid in analysis, they often serve different functions. Frameworks are broader structures that may include multiple theories or concepts but do not necessarily aim to provide comprehensive explanations. Models usually simplify reality to illustrate specific concepts or relationships, focusing on particular aspects rather than offering a complete theoretical understanding. Hypotheses are specific, testable statements derived from theories and typically require empirical observations to validate them. Therefore, while they are essential components of the research process, they do not serve as overarching tools for organizing the entirety of international relations in the way that theories do.