Much like physics, international relations can be divided into two worlds: a stripped-down, normative world of theory, and a full-fat, often unclear and contradicting "real life." Like the vacuumed, frictionless world of ideal physics, IR theory streamlines nations into hyper-rational, calculating "State As" and "State Bs" that make decisions predicated upon game theory modeling. These choices always result in the ideal outcome for one or both sides. Meanwhile, IR scholarship of the historical record, analyzing the messiness of the real world, is often content merely to explain how things are, rather than how they should be. Where an IR theory elegantly traces ideal models that vaguely echo real life, pure historical analysis steals bits and pieces of disparate theories to graft a sometimes-contradicting "model" onto the real world.
Source: Washington Free Beacon