Peterson, investment banker and chairman of the Council on foreign Relations, applies demographic projections to forecast a titanic collapse of entitlement policy throughout the industrialized world: rich countries are not reproducing fast enough to offset the wave of aging in the 21st century. Poorer countries, starting with China, are likely to follow, leading to the eventual decline in world population. Past legislation has funded pension and health care rights for the aged largely through current taxes -- and as the proportion of the elderly grows, honoring these entitlements in full will become highly problematic. Although the American Social Security system is in good shape compared with Europe, all are in trouble. Peterson skillfully addresses potential solutions and finds none easy, especially as "gray" political influence grows. He offers fascinating and sometimes provocative speculations -- intending to raise questions rather than provide answers -- on the implications of the demographic crunch for domestic politics, the family, capital markets, medical ethics, trade policy, and international relations. Nevertheless, the book disappoints in one respect: it offers only a cursory discussion of the potential of increased immigration from poorer, younger nations as a way to alleviate the aging problem -- at least for the United States and other rich countries open to immigrants.