It is politically correct to speak of the enrichment and opportunities that follow from multiculturalism and diversity. However it would be naive to not acknowledge that it also brings new problems.
Still I think there is a danger in presenting the problems caused by multiculturalism as inherent and immutable. I think a large part of the problems caused by multiculturalism stems from the fact that different groups of people don’t believe a diverse population can live together. Thus instead of trying to find ways of bridging the gap, they spend their energy on either secluding themselves, trying to blame or contain the other group.
What is Diversity?
Not every form of diversity is of significance with respect to the ability of people to get along. You speak of the 19 religious denominations of evangelicals in the US. However I don’t think that is a source of conflict. In the 1500s Europe had one of its bloodiest wars, the 30 years war between catholics and protestants. Deep seated historical conflicts between Irish and British has been founded on this conflict between catholicism and protestantism. It seemed like a revolution when catholic John F. Kennedy got elected in he US. Yet this kind of conflict between different Christian denominations are no longer of much significance.
There was a time when people denoted as WASP and PIGS could not get along, that time is past. In my native Norway, there was great animosity between Northern Norwegians and Southern Norwegians. In the 60s ads in Oslo for rental would specifically state that Northern Norwegians were not welcome.
Today in the West the main source of conflict with respect to religion is between Islam and western secularism. There tends to be a higher portion of muslims in Nordic countries than in the US, and thus with respect to religion, one could argue that diversity of significance is higher than in the US.
I think it is somewhat pointless to pick arbitrary measures of diversity to make a case. You got to look at what matters. It is easy to pick an area where the US is diverse and avoid areas it is not. E.g. the US has very little diversity in language compared to most European countries. Norway in particular has very large variation in dialects and pronunciations, to the point where on could not agree on one written language but instead have two.
Crime Rates Across Homogenous and Diverse Countries
The crime rates in Nordic countries (and places like Hong Kong, Singapore, Japan, etc…) aren’t lower because of policies or politics. The policies and politics exist as they are because your populations are monocultural and homogeneous.
But that is not an argument against those very policies. It may be an argument for why those polices are harder to enact but not an argument for not enacting them. Singapore by the way is not homogenous. In fact it has a rather troublesome history.
Look at the list of countries ranked by homicide rates and by and large, the more homogeneous the population of the country is, the lower their homicide rate (and crime rate in general).
Superficially, yes. However one can find plenty of counter examples. In particular I ask you to compare South America, the Caribbean and Africa. Jamaica e.g. is quite homogenous. Most people are descendant of African slaves, and the culture has been mixed as to not be significant religious, ethnical or language diversity to my knowledge. Yet Jamaica has a staggering homicide rate of 47.
Rwanda in contrast has a mere 2.52 rate, despite the fact that we know they are anything but homogenous. The Rwanda genocide happen specifically due to the conflict between Hutu and Tutsi.
This is the case across much of Africa. Country borders were unnaturally setup by European colonizers and thus a wide variety of different ethnic groups live within the same country. This has also helped fuel numerous civil wars in Africa in the past. Yet despite this it is possible to bring change, Rwanda is turning into model country of development. Many other African countries have managed to make peace and move ahead. They now have considerably lower homicide rates than South American and Caribbean nations.
Counter Examples and Capacity for Change
If the overwhelming majority of a given population is all of the same genetic ancestry, follows the same religion, has the same cultural traditions, etc.. what’s left to argue about? There is no “Us vs. Them” situation present when everyone is “Us”.
In a static view of the world, that is true. However ethnicities and nations are not fixed immutable entities. Through deliberate policies a nation can come together. Rwanda is one example. Singapore is another great example. It has a homicide rate of only 0.32 despite being a very diverse place ethnically. Other diverse places with fair low crime rate includes Australia at 0.94, New Zealand at 0.99 and Canada at 1.68.
In short there is an abundance of counter points to the claim that diversity causes high crime rates.
However it is hard to not notice a very consistent pattern of extreme violence and crime in nations with a nasty past of brutal suppression of minorities, slavery or racism.
Forging Unity from Diversity
Politics matter. Americans tend to view European nations as fully formed homogenous ethnic states. This is a largely an illusion. Most European states were forged over hundreds of years from a very diverse set of people. The Netherlands and Belgium are not much older than 400 years. Before that there was no Dutch or Belgian identity. They were different enough that the Dutch first fought an extremely bloody war with Spain for independence before Belgium and the Netherlands was formed from a Civil war in yet another conflict. Even the tiny British islands have seen hundreds of years of conflict and bloodshed. Welsh, Normans, Saxons and Scotts were all merged into one nation. National languages such as German and French are largely modern inventions.
Even Nordic countries help up as the stereotype of homogenous harmony were made that way through deliberate polices to create single national identities. The 30s was anything but harmony. Politics was polarized between the working class and bourgeois. Norway was a class society. Striking workers were gunned down by the police. Oslo was a divided city between the wealthier west side and working class east side. They had their own sports teams and lived mostly parallel lives. The experience of Nazi occupation was a first step in getting people on both sides of the divide to start working together towards common goals. The labour party spent a lot of effort on reducing inequality and tearing down class society.
So I would disagree with the notion that harmony is what makes certain politics possible. It also works the other way. Politics can be used to create harmony. That not only happened in Norway after the war but was also crucial in forging national unity in Rwanda and Singapore.
Change Cannot Happen if You Don’t Believe in It
It is provocative when people insinuate that diversity makes harmony impossible. There is a combination of an underlying defeatism and racism in that suggestion. The US has good historical reasons for its struggles. I am not denying that. I am denying the idea that the US cannot move forward. Enacting Norwegian style prison policies maybe lot harder in the US, but it is not impossible to move in that direction.
The best proof of that is that the State of Texas no less has started moving in that direction. This is a republican, tough on crime strong hold. Yet they realized this approach simply does not work. The prison population just kept swelling year after year depleting state budgets. If there is anything republicans care about it is money. They care about low taxes, and that cannot happen when you got a runaway prison system. They started prison reforms aimed at rehabilitation rather than revenge like Norway. They saw costs drop and recidivism rates drop.
If Texas can do it, there is no excuse for the rest of the US ;-)