By 2050, the U.S. will have 34 retirees for every 100 working-age people, vs. 21 now, according to U.N. projections. Japan will have about 78 for every 100 20-to-64-year-olds, and Europe, 60. (WOW! from here)
USA's current account defecit went from balance in 1991 to 5.7% of gross domestic product in 2004. (ibid)