Neoclassical realist research program for the 21st century: From topography and traditions to an abductive practical guide

A novel case for the neoclassical realist (NCR) scientific research program is made via a rigorous yet practical expert guide, integrating insights from six theoretical traditions – Rosean, Cadillac, Aronian, Munich, New European, and Global – structured by eight targeted abductive questions and demonstrated across four contemporary empirical scenarios. It first maps NCR’s topography through an analysis of 265 scholarly works, highlighting extensive geographical and theoretical diversity. In complementary fashion, it identifies six NCR traditions – both implicit and self-declared, some extant, others emerging – each analytically powerful across diverse regions: the US-based Rosean and widely exported/indigenized Cadillac traditions; two traditional European yet overlooked schools, philosophical Aronian and synoptic Munich; the converging New European tradition; and the emerging Global NCR emphasizing non-Western yet still realist perspectives. In their identifying, we explicitly reject inter-theoretical fusion, set clear criteria, and maintain meta-theoretical coherence within realism. Each tradition has distinct epistemological orientations and explanatory logics, challenging prevailing views of NCR as merely a unified American extension of structural realism. The article introduces an original abductive comparative framework structured by eight guiding questions addressing analytical purpose, historical timeframe, systemic-domestic drivers, leadership/regime characteristics, degree of Westphalian sovereignty, revisionist-status quo orientations, alliance patterns, and nuclear/advanced-deterrence considerations. Positive heuristics of an abductive approach to NCR is demonstrated across four empirical scenarios – War in Ukraine, Sino–US rivalry, Saudi–Iran balancing, and Brexit/European Union (EU) crisis – optimizing puzzle fits and enhancing theoretical precision, explanatory coherence, and empirical sensitivity. This approach offers scholars directly comparable theory lines to tackle complex international dynamics in the 21st century.