A Tyrant 40 Years in the Making By ROGER MORRIS SEATTLE — On the brink of war, both supporters and critics of United States policy on Iraq agree on the origins, at least, of the haunted relations that have brought us to this pass: America's dealings with Saddam Hussein, justifiable or not, began some two decades ago with its shadowy, expedient support of his regime in the Iraq-Iran war of the 1980's. Both sides are mistaken. Washington's policy traces an even longer, more shrouded and fateful history. Forty years ago, the Central Intelligence Agency, under President John F. Kennedy, conducted...