People are united by the things they share in common - a common language, a common history, a common set of political values, a common set of moral principles - to name the most important. Race and religion are also factors, but the divisions engendered by racial and religious diversity are suppressed when those other commonalities are present, as they have been throughout much of our nation's history.
When people share common values and a common language they can, and do, overlook racial and religious differences, but when none of those commonalities exist society becomes Balkanized into ethnic, racial and religious interests groups all seeking to achieve power over the others. Each group becomes a tinder box of resentments, grievances, and hatreds.
This, apparently, is what we see happening in Europe, and the Europeans are starting to admit publicly what they used to try to sweep under the rug - multiculturalism is a failure. The most recent European leader to make this unpleasant admission is Germany's Angela Merkel:
Germany's attempt to create a multi-cultural society has failed completely, Chancellor Angela Merkel said at the weekend, calling on the country's immigrants to learn German and adopt Christian values. Merkel weighed in for the first time in a blistering debate sparked by a central bank board member saying the country was being made "more stupid" by poorly educated and unproductive Muslim migrants.
"Multikulti", the concept that "we are now living side by side and are happy about it," does not work, Merkel told a meeting of younger members of her conservative Christian Democratic Union (CDU) party at Potsdam near Berlin.
"This approach has failed, totally," she said, adding that immigrants should integrate and adopt Germany's culture and values.
"We feel tied to Christian values. Those who don't accept them don't have a place here," said the chancellor.
"Subsidising immigrants" isn't sufficient, Germany has the right to "make demands" on them, she added, such as mastering the language of Goethe and abandoning practices such as forced marriages.There's more at the link. The United States is a nation of immigrants, of course, but until relatively recently those immigrants insisted that their children speak the language, embrace the traditions, and value the freedoms enshrined in the Bill of Rights. That has changed, however. The concept of assimilation has fallen out of favor. The Left considers it an expression of cultural chauvinism and takes every opportunity to denigrate those very values and traditions. If this trend continues, and it will as long as the Left maintains its cultural hegemony, it will not be long before the U.S. starts looking like Bosnia.