What kind of 'permanent interim' would it be, though? As dylans has said, the Palestinian side of a 'two-state solution' would not be a viable, independent entity. It would be dependent on Israel, and as such, the so-called 'two-state solution' isn't really that at all. If he favours this as some kind of permanent fudge, what he's really advocating is a permanent marginalising of the Palestinians. That's no solution at all, and won't be seen as a solution by the Palestinians it marginalises, and so it is simply a continuation of the conflict on different terms.