The White House says it with sorrow. The Israeli prime minister says it with impressive determination. Pundits say it as though it is stone-carved truth. We must not reward terrorism -- by demolishing the West Bank settlements, by negotiating with Yasser Arafat (or even accepting the legitimacy of his leadership), by withdrawing Israeli troops from Palestinian territory or, above all, by seriously pushing for Palestinian statehood. The admonition is repeated as though its meaning is crystal clear. But what, in fact, does it mean?