Are airstrikes an effective tool against insurgent organizations? Despite the question's historical and contemporary relevance, we have few dedicated studies, and even less consensus, about airpower's effectiveness in counterinsurgency wars. To answer this question, I draw on declassified United States Air Force records of nearly 23,000 airstrikes and non-lethal shows of force in Afghanistan (2006-11), satellite imagery, and a new SQL-enabled form of dynamic matching to estimate the causal effects of airstrikes on insurgent attacks over variable temporal and spatial windows. Evidence consistently indicates that airstrikes markedly increase insurgent attacks relative to non-bombed locations for at least 90 days after a strike. Civilian casualties play little role in explaining post-strike insurgent responses, however. Instead, these attacks appear driven by reputational concerns, as insurgent organizations step up their violence after air operations to maintain their reputations for resolve in the eyes of local populations.