There's an important and counterintuitive lesson for all nations in the fate of the Crimean Peninsula: If you want to keep a territory from seceding, set its people free.

As Spain's efforts to quash a Catalan sovereignty movement demonstrate, nations typically do not tolerate breakaway regions under any circumstances. This was certainly the case with Ukraine, which held tightly onto Crimea after breaking away from the Soviet Union. Is that wise?

International law is unclear on the matter of secession. In its 2010 advisory opinion on the Kosovo independence declaration, the International Court of Justice, the United Nations' judiciary arm, said that "it is entirely possible for a particular act — such as a unilateral declaration of independence — not to be in violation of international law without necessarily constituting the exercise of a right conferred by it." In other words, even if regions do not have an explicit right to self-determination, the act of secession might not be illegal.