ByJohn S. McClenahen Second only to the question of when the U.S. will intervene in Iraq is will the Federal Open Market Committee (FOMC) lower short-term U.S. interest rates at its scheduled Sept. 24 meeting. Chairman Alan Greenspan and his colleagues are likely to leave the influential federal funds rate unchanged at 1.75%. The U.S. economy is adding jobs -- though at a very slow pace. And in August, the unemployment rate fell unexpectedly to 5.7% from its 5.9% July mark. And that's enough, says Maury Harris, chief U.S. economist at UBS Warburg LLC, New York, to believe that the FOMC will leave the federal funds rate unchanged this month -- and through the end of 2002.