At the close of a speech on women's contributions to global prosperity, I was asked to predict what the U.S. workforce would look like in the coming decades. My mind fixed on the image of all those Catholic churches I've attended where mostly women fill the pews -- even though the Vatican's men are firmly in charge. If current trends continue, we're heading toward a 21st-century workforce in which senior roles remain solidly male and women are the strivers. Absent from the picture? Rank-and-file American men, who increasingly are falling behind and becoming far less equipped than women to land promising jobs.