The latest Israeli-U.S. clash over construction in east Jerusalem indicates again how difficult it's going to be to shape the regional reality Barack Obama desperately wants. That's why there's a new deluge of policy proposals - not least of which is Israeli President Shimon Peres's trial balloon: a Palestinian state with provisional borders, leading to a permanent Israeli-Palestinian deal. Both parties officially reject the idea. But if properly formulated, it just might be a way of satisfying key Israeli and Palestinian needs.