This book describes some of the problems that currently exist in the United States when different populations of people exist in the same environment. We look at populations of undocumented aliens, radical religious groups and the welfare state. We vary the size of these populations and determine the resulting stability of of the country. As each of these populations grows, the systems become more unstable, Citizens become concerned about the population growth and its affect on the country as a whole. one of the major concerns is that supporting these unwanted populations can have a serious affect on the quality of life of citizens. The author has watched this situation grow for over five decades and believes that if the current situation is not effectively addressed, the United States will will decline in its role as a first class nation.