Today, the Pentagon announced the rescue, by the U.S. Navy, of 13 Iranians who had been held captive by Somali pirates since last November. The Iranians are on their way home, and the pirates are in U.S. custody. How can the international community crack down on piracy?

A 2010 report from the Council on Foreign Relations offers some suggestions. The report gives reason to doubt the efficacy of onboard deterrents. For one, crews on most ships aren’t trained in the use of weapons, and they fear that if the ship is attacked, the people holding guns will be targeted. Professional guards, moreover, are expensive, and private security firms have had a hard time finding clients. Naval deployments and regional cooperation in piracy hotspots seem to have some effect, but many experts caution that navies are best equipped for fighting wars—not policing the high seas. Others have suggested creating a coast guard in Somalia (the overwhelming number of hijackings take place off that country’s coast), but such an effort could prove logistically daunting. Of course, it’s also a daunting task to develop the “only effective long-term piracy deterrent” that all experts agree on: “a stable state.”