Yes, both sides must come to an agreement.
But Bush has thrown away what little credibility we have as an honest broker who will reward and punish both sides as necessary to move them toward an agreement. It gives ammunition to the radicals who believe that we're deciding and helping to implement Israel's policies. He's undercutting his own Roadmap for Pete's sake.
Indeed, it may take another 20 years. It'll probably take longer if Bush is re-elected. :-(
Sharon and Arafat both know they don't have much time left in this world. Approaching death can bring a certain sharpening of focus to people who still have their faculties, but I don't know if Arafat and Sharon are in that category...
Cheers,
Scott.