We all know the story: a grisly murder has unleashed a storm of controversy. The legal and procedural maneuvering aside, the killing has greatly heightened the tension and polarization between the population at large and the alleged killer's minority group. It is a group that has never integrated fully into the larger society, with increasing numbers of its members linguistically separating themselves from the majority, and embracing a grievance-based radical form of Islam. Among the majority, it has come to be associated with unemployment, poverty, crime and drug use. Its alienation level can be judged by the disturbing amount of support its more radical members have lent the alleged murderer.

On the other hand, this alienation is also born of resentment of years of discrimination and hostility, as symbolized by the use of racial epithets that gained wide attention in the aftermath of the murder. There has been much talk of a massive, ugly backlash.

So what were the long-term consequences of the O.J. Simpson case, anyway?

One of the most remarkable non-events in contemporary American politics is the virtually complete disappearance of the issue of race from the national debate--only to reappear, with a vengeance, across the ocean, in Europe. Less than a decade ago, the O.J. Simpson trial--occurring three years after the L.A. riots, and 4 years after the Crown Heights riots--seemed to demonstrate a vast, impenetrable wall of hostility and fury along the American racial divide. Tons of ink and millions of pixels were used up discussing this divide, its causes, its implications and its possible solutions. Today, while Europeans grapple with the same thorny issues (with the same air of earnest gravity), Americans barely give the issue a passing thought. People on both continents would surely benefit from knowing how that remarkable transformation occurred.

Some possible factors:

9/11.Of course, nothing unites people like a common enemy. Both black and white Americans may feel less hostile towards each other now that they consider themselves equally threatened by terror. News and political debate about terrorism have also probably crowded out other issues, including race relations.

On the other hand, racial tension seemed to be on the decline even before 9/11, and the actual evidence regarding 9/11's effect is ambiguous.

The drop in crime. Crime dropped fairly steeply during the 1990's, for both races, although blacks maintain their proportional lead in both victimization and victimhood. Crime may well have been an important source of racial tension, feeding feelings of resentment among whites (over disproportionately high crime rates among blacks) and neglect among blacks (over less effective crime control in black neighborhoods). Declining crime might therefore have led to improved race relations.

On the other hand, isolated crime-related racial conflicts over racial profiling and police shootings (for example, in Cincinnati) have continued, despite plummeting crime rates.

Welfare reform. The 1996 welfare reform bill is widely credited with undermining the culture of inner-city welfare dependency that was a source of much white resentment and anger, and motivated no end of racially-oriented activism. Then again, it doesn't appear that perceptions of inner-city black culture have changed all that much.

Immigration. As a friend points out, immigration complicates America's racial mix, and may therefore have reduced the importance of the original black-white conflict. Of course, extra axes of racial interaction haven't always encouraged calm.

Time. Racial hostility may simply have continued the slow, gradual decline it began following the civil rights battles of the 1960s. The boom of the nineties, by reducing black unemployment and income inequality, may have helped matters by reducing the economic--and hence the social--distance between blacks and whites. Perhaps a tipping point of sorts was reached, at which tensions subsided enough to slip beneath the social radar entirely.

On the other hand, racial integration--widely considered an indicator of long-term progress in race relations--increased only modestly, and in some ways actually decreased, during the 1990s.

As you can see, there are many somewhat plausible explanations, and none of them are without compelling counterarguments. Readers are encouraged to offer their own diagnoses, by posting comments. Perhaps our European onlookers will be able to use our ideas to help them identify possible solutions to their own version of the same problem.