What Iran teaches us about why wars start

War is fundamentally an exception in international relations because of its extreme economic and human costs. While most conflicts are brief, long-term wars persist due to specific structural and psychological drivers. Chris Blattman, an economist and political scientist at the University of Chicago, identifies five key factors that push nations toward prolonged violence: leaders who do not bear the direct costs of conflict, intangible incentives like ideology or vengeance, deep uncertainty regarding an adversary's strength, commitment problems—such as the Thucydides trap where a declining power fears a rising one—and critical misperceptions or overconfidence. Although groups often harbor mutual loathing, all-out war remains rare because the high costs typically incentivize restraint. Understanding these mechanisms reveals why some conflicts escalate into protracted struggles while others remain contained within short-lived, manageable skirmishes.