In the ascription of causality in international relations (IR), there is either deliberate action or historical contingency. Historical contingency is an element that cannot be accounted for; however, deliberate action is accounted for and ascribed to planning or strategy. Even with strategically planned deliberate action, there is an element of uncertainty of whether the intended effect will be achieved or not. This is due to intended effects of strategy being mediated by situational variables and contingencies. These characteristics form the underlying implicit nature of strategy.