Visiting Israel on the first part of his Middle East tour, President Bush is hitting all of the right notes. In his joint press conference with Israeli Prime Minister Ehud Olmert in Jerusalem yesterday, Dubya took pains to stress that he still considers Iran a threat that must be confronted, and leaned hard on the need for Palestinians to play a more constructive role in guaranteeing Israel's security. Not surprisingly, though, there were not many specifics about exactly how he plans to deliver on both counts.