The Hundred Days is indelibly associated with Franklin D. Roosevelt, and the Thousand Days with John F. Kennedy. But as of this week, a thousand days remain of President Bush's last term -- days filled with ominous preparations for and dark rumors of a preventive war against Iran.The issue of preventive war as a presidential prerogative is hardly new. In February 1848 Rep. Abraham Lincoln explained his opposition to the Mexican War: "Allow the President to invade a neighboring nation, whenever he shall deem it necessary to repel an invasion and you allow him to do so whenever he may...