HWP, do mockingbirds mate with blue jays? They’re both birds, but they stay with their own kind. Do chameleons mate with geckos? No, each type couples with its own kind. All manner of birds can fly the skies together, perch on the same branches and hop around on the same fields, but they “know” that reproduction is reserved for their own kind.
The question you ask, OP, has biological ramifications (for example, sickle cell anemia being imported into a much wider population), as well as cultural ramifications (which include politics and religion). In our heavily fascist PC era (and as a result of the debacle of Nazism), we are not allowed to calmly discuss this topic, but it needs to be. The Soviets tried to pave over the whole issue, pretending it was a non-issue, yet look what happened as soon as that atrocity-ridden system crumbled: renewed ferocious hostility between the races.
I submit that the modern taboo on discussing this subject is our counterpart to the Victorian taboo on discussing sex. There is no justification for the ban other than that certain powerful minorities (the ones controlling all the organs of influence in Western society) have managed to propagandize the majority into squeamishness, using the handy cudgel of “hate speech” and “hate crimes” as their weapon of choice.
Here is my question back to you: if all races are equal, then why are there such deep disparities between them culturally? Why do people like the Jews and the Japanese, races that endured the most horrendous of massacres, resurge like the Phoenix, while other groups, who endured lesser hardships (or comparatively none), actually get worse (more crime, illegitimacy, drug use and sales, etc.), even after decades of billions of dollars in subsidies?
Even the apostle Paul himself refers to the Cretans of his time as being lazy and liars. Will the Berias of today excise that passage out of God’s Word because of our wussy Gleichschaltung du jour (this time from the Left)? There are others who gnash their teeth at the references to “the Jews” in John’s gospel. The new RSV is already “gender neutral” (AlkaSelzer, please); will future editions simply drop that gospel entirely? Orwell’s prescient warnings notwithstanding, it would seem that Big Brother has definitely made great strides.
[Note to Tsuwano: my comments are not meant to belittle your choice. I personally see no problem with, for example, a Japanese and a Caucasian marrying—because I don’t consider the Japanese a different race.]