The drama in Ukraine has occupied global headlines for many months now and — while there are occasional signs that things are calming down — the overall picture is not pretty for any of the parties involved. It did not have to be this way. Even assuming that Crimea was inevitably going to end up a part of Russia, international law could have facilitated a peaceful transfer that would have helped align the parties’ interests rather than putting them at odds. The mechanism for this is what we call a “market for sovereign control.” The idea is straightforward. If one country (say, Russia) values a region (Crimea) in another country (Ukraine) enough, it should be willing to pay for it. If the people of the region and the parent country agree to the offer, then the border can be moved without any need for chest-pounding and troop movements. With such a system in place, Russia could have bought part of Ukraine instead of breaking it.