Book excerpt: Smith (economic policy, Stanford U.) looks at some of the tough questions facing the North American neighbors in light of such often forgotten facts as that by 1853 one-half of what used to be Mexico had become one-third of what is now the US. Looking at the increasing interdependence at many levels, he predicts that drug trafficking is likely to continue and the illegal immigration likely to increase. Annotation copyrighted by Book News, Inc., Portland, OR