Britain's late Prime Minister Margaret Thatcher said it all when she wrote that the world has "never ceased to be dangerous," but the West has "ceased to be vigilant."
Nothing better illustrates her point than the fact that the West has imported vast numbers of people who hate our guts and would love to slit our throats. Political correctness has replaced self-preservation. The Boston Marathon killer who set a bomb down right next to an eight-year-old child is only the latest in an on-going series of such people.
Sen. Patrick Leahy has warned us not to use the Boston Marathon terrorists as an argument against the immigration legislation he advocates. But if we are not to base our laws on facts about realities, what are we to base them on? Fashionable theories and pious rhetoric?
While we cannot condemn all members of any group for what other members of their group have done, that does not mean that we must ignore the fact that the costs and dangers created by some groups are much greater than those created by other groups.
Most members of most groups may be basically decent people. But if 85 percent of group A are decent and 95 percent of group B are decent, this means that there is three times as large a proportion of undesirable people in group A as in group B. Should we willfully ignore that when considering immigration laws?
It is already known that a significant percentage of the immigrants from some countries go on welfare, while practically none from some other countries do. Some children from some countries are eager students in school and, even when they come here knowing little or no English, they go on to master the language better than many native-born Americans.
But other children from other countries drag down educational standards and create many other problems in school, as well as forming gangs that ruin whole neighborhoods with their vandalism and violence, and cost many lives.
Are we to shut our eyes to such differences and just lump all immigrants together, as if we are talking about abstract people in an abstract world?
Perhaps the most important fact about the immigration bill introduced in the Senate is that its advocates are trying to rush it through to passage before there is time for serious questions to be explored and debated, so as to get serious answers.
Anyone who suggests that we should compare welfare rates, crime rates, high school dropout rates, and drunk-driving arrest rates among immigrants from different countries, before we set immigration quotas, is likely to be stigmatized as a bad person.
Above all, we need to look at immigration laws in terms of how they affect the American people and the American culture that gives us a prosperity that has long been among the highest in the world.
Americans, after all, are not a separate race but people from many racial and ethnic backgrounds. Yet most Americans have a higher standard of living than other people of the same racial or ethnic background in their respective ancestral home countries. That is even more true for black Americans than for white Americans.
Clearly, whatever we have in this country that makes life here better than in the countries from which most Americans originated is something worth preserving. A hundred years ago, preserving the American way of life was much easier than today, because most of the people who came here then did so to become Americans, learn our language, and adopt our way of life.
Today, virtually every group has its own "leaders" promoting its separate identity and different way of life, backed up by zealots for multiculturalism and bilingualism in the general population. The magic word "diversity" is repeated endlessly and insistently to banish concerns about the Balkanization of America — and banish examples provided by the tragic history of the Balkans.
We are importing many foreigners who stay foreign, if not hostile. Blithely turning them into citizens by fiat, rather than because they have committed to the American way of life, is an irreversible decision that can easily turn out to be a dangerous gamble with the future of the whole society.
What happened in Boston shows just one of those dangers.
Thomas Sowell is a senior fellow at the Hoover Institution, Stanford University. Read more reports from Thomas Sowell — Click Here Now.