There is a striking difference between how members of certain nations, ethnic groups and religions behave in the Old World and in the New. They are mortal enemies in their native homes. The struggles between Muslims and Christians, Bosnians and Serbs, and Hutus and Tutsis display a vicious stridency. The embers of their enduring hatred create conflagrations of violence again and again.

By comparison with this fury, the relation in America of Old World antagonists is surprisingly tame. Traditional enemies live at peace with each other, in many cases in the same apartment buildings. Genocidal tendencies remain in check, and instead of laboring to make others miserable, people endeavor to make themselves happy.

What accounts for this amazing change of attitude? There are enough Muslims and Hindus in the United States to create deadly clashes over their differences. But they don’t. The police in major American cities would not sit back while zealots bombed religious sites. But large-scale police action just isn’t needed.

Telephones and the Internet expose immigrants to agitation from their native lands. But what is incendiary in the Old World falls on deaf ears in the New. That Palestinians and Israelis kill each other in the Middle East seems not to be a good reason to do likewise in the United States.

To explain the change in attitude, we must look at what immigration to America involves. To the new arrivals, the change is excruciating. Learning a new language and dealing with strange customs make the first years of life in the new land painful. Like the last snow of winter, however, the misery hides fresh growth: the habits and values of the Old World are replaced with those of the New.

The new values arise not through coercion but by freely doing what others do and wanting the same things they have. Hungarians who arrived in New Jersey after the 1956 revolution were outraged at what was expected of them at work. Some grumbled that Soviet repression was preferable to having to expend so much energy each day. Yet within a few years, they were taking trips to Bermuda, saving money for houses and working their hearts out to get promoted.

The economic system of the United States is a mighty engine of persuasion. It motivates people to do what otherwise they never would in return for fulfilling their dreams. In the process, people learn that there is no sharp line between physical well-being and the higher purposes of life. The comfort of owning a house is at once meeting the obligation to care for one’s family. Financial success is the foundation of helping those in need.

Material means make miserable ends, but properly used they are indispensable for accomplishing the good.

Some advocates of high culture heap scorn on commercial life. They overlook the affirmation of human dignity through freedom of contract that is its ground and the reduction of suffering through plenty that is its product. They forget that the goods of this world are essential for doing good in the world.

Immigrants to America appropriate local ideas of success with astonishing fervor. Social stability makes their possessions secure and their long-term plans effective. The hope that the future will be better pervades American life. The conviction that tensions can be defused and problems solved turns the mind from grief over the past toward concrete steps to improve life.

Is this attitude unique to the United States? It neither is nor has to be. It pervades any nation that provides material improvement for its people. Prosperity undercuts ideological intolerance: envy and destructive anger do not flourish among people who live comfortable lives and expect a happy future.

The Old Testament speaks of a promised land. If already occupied by others, this can become the source of endless conflict. What people need instead is a land of promise, which America has been for a long time, and other sensible nations now try to become.