20 other. Wars are notorious for yielding unintended and unexpected consequences; for reasons explained below, a war against Iran is even harder than usual to bound analytically. Complexity, Uncertainty and War Our first consideration in analyzing the likely course of war with Iran is that a U.S.-led attack would be merely the first phase of a war, the opening act of an extended drama whose scenes would unfold, not according to any script, but to an emergent logic of its own. Given the political context in which military engagement would rest, even a minor attack would likely become a major test of strength involving not only the United States and Iran but also a host of allies and associates. It is therefore disingenuous to try to frame military action against Iran as a simple “raid” or even a broader “operation.” We are talking here about war, with attendant potential high costs to all combatants in terms of military casualties, civilian damage and economic disruption. At least three concepts are key to any coherent discussion of a U.S.- Iranian military engagement: complexity, uncertainty and war itself. By complexity we mean the number of moving parts in a given situation: actors, processes and the connections among them. By uncertainty we mean structural uncertainty—that is, not just ignorance of the magnitudes of agreed casual factors, but the ignorance of the causal factors themselves, and their mutual relations. For example, not only may the U.S. government not know, say, the technical status of the Iranian nuclear program, or the actual state of readiness of Iranian forces. It may not know (or worse, have wrong) the decision-making and implementation protocols of the Iranian government, how the Iranian people and military would react to an attack, what Tehran would ask its allies and proxies to do, and what in fact they will do. HOUSE_OVERSIGHT_018104