On March 19, 2011, the United States and nineteen allied states launched an air assault against the Libyan military. President Obama and other leaders argued that military action would protect Libyan civilians, aid the progress of democracy there and across the region, and buttress the credibility of the U.N. Security Council, which had passed a resolution demanding a cease fire. By October, local rebel militias had killed Libya’s long-time ruler, Muammar el-Qaddafi, and overthrown his government. Three years later, it is time to ask whether the intervention worked. Did it protect Libyans or, by prolonging the civil war and creating political chaos, heighten their suffering? Is Libya becoming a stable democracy, a failed state, or something else? Did the intervention help other revolutions in the region, heighten repression of them, or was it simply irrelevant? Should the United States help overthrow other Middle Eastern dictators?