I spent a year and a half enforcing "no-fly" zones over Iraq and the Balkans. My experiences convinced me that the United States should declare and enforce a no-fly zone over Syria. We would do well to remember the era of no-fly zones and what they did and didn't do.

Those who oppose a no-fly zone cite the risks: Syria has a formidable air-defense network. Policymakers fear the prospect of U.S. pilots being shot down or dragged through the streets of Damascus. Moreover, many contend that a no-fly zone will not solve the conflict. Only by arming the rebels will the tide be turned, they say, and many of those rebels are jihadists with whom we do not want to partner.

Critics of a no-fly zone also fear a slippery slope of escalated military involvement that will lead to a quagmire.