I think if you're talking about racial integration, then you have to understand it is an applied concept that has been around for over forty years. It wasn't wide spread when the laws were formed to mandate it, so it has been gradual. On the everyday side of things, it's harder because even though my generation and younger generations because diversity is prioritized but not actively practiced. It was still an issue of white kids vs. black kids for one reason or another and in a lot of cases it was because of educational differences, cultural differences, and so on. It's never going to be perfect, but I think people have to open their minds to life being a series of changes and one important change should be we shouldn't see color, but character. Until that can happen purely, integration will always be a work in progress.
There will be no total racial integration as long as there is self-imposed segregation.
For example: There is a Miss America contest every year. All women of all races are invited to compete for the prize. There is also a Miss Black America and Miss Latina America..... Those two latter do not invite Caucasian women or Asian women to join in the competition.
In Houston, Tx there is a Fireman's Association, where all members of the firefighter community can join, and a black fireman's association.
In Congress there is a Congressional caucus, and a Black Congressional caucus.
We are no longer American, but we are African-American, Latino-American, Asian American, European-American.
As long as there is self-imposed segregation by choice of each racial group, there will never EVER be integration.
The hyphenated-American, thanks to Reverend Jesse Jackson, has caused a back-step in the process that Dr. ML King fought for in the 1960's. And THAT only took 20 years to change, and ruined decades of attempts at equality.
Not sure what you mean by "world integration." I seems to me with technological advances from sailing ships plying the oceans to air transportation to the Internet we have no choice. There's no holding it back. There are pluses and minuses. American manufacturing workers are losing their jobs to poorly paid Chinese workers in unsafe, polluting plants, and American citizens are benefiting from cheap Chinese imports, not always of good quality. Civilization advances and is envriched through cross-cultural communications and education but the recent downside has been the increase in terrorism. There is no simple answer to your question other than "We have no choice but to make integration work," in my opinion.