There are three good reasons why the United States should worry about Iraq: oil, weapons of mass destruction, and Saddam Hussein. Iraq has the second-largest oil reserves in the Mideast, and what its government does with them vitally affects the world economy. As for weapons, Iraq already possesses chemical and biological weapons and could soon acquire nuclear ones. And Saddam, besides brutalizing his own people, has been willing to pursue reckless foreign-policy adventures -- in Iran (1980) and Kuwait (1990) -- that put the region at risk. Armed with nuclear weapons, he could wreak havoc.