A one-state solution is inherently a political disaster, a recipe for permanent divisiveness and conflict. However it starts out, there will be calls to limit Palestinian political power, to limit the definition of citizenship as it applies to Palestinians. Jewish and democratic? Take your pick; you can't have both in one state. (And you might well end up with neither.) Back, therefore, to two states. Two states may not be a perfect solution, merely the only one that makes sense.