The plan is to attach oneself to existence for as long as possible like a limpet on Britain's political system, which like many others is more about holding position than actually holding to your promises. As for multicultural integration, this is such a convoluted area where to start? For one the introduction of foods, clothes and other material goods from other countries could be considered a success of multiculturalism, but at the same time the integration of different values is an objective that appears almost designed to fail.
I'm not saying people need to hold the same values either, but this happens because at some point different views conflict and people can get very emotionally attached to their views; to the point of rabid idealism. To me there are very few clear answers which don't involve one group losing out in some fashion. But I don't believe there are overarching conspiracies to homogenise, merely hundreds of different influences that are usually self-serving but affect whole swathes of a population. Now I do believe that everything we do is ultimately driven selfishly, but I don't think that is such a bad thing. Our group selfishness can meet selflessness coming the other way if we can agree for 5 minutes on a course of action or thought.
This is where tolerance comes in, tolerance allows someone to put up with something that they don't necessarily like or accept. But with a value this doesn't work, because it informs the actions of the individual (especially if it is held as an ideal) and when it translates into action then you get real conflict with physically harmful results.
But I suppose really, the problem is also massively compounded by unbalanced people who cannot accept an opposing view without violence and then sometimes it's the excuse for violence, or the pretext for gaining power...etc..
These harmful motivations, when enacted, cause such an outrage of fear and anger, that all rationality is thrown out in favour of reactionary disciplines or actions. It's hard to pick apart because the world keeps getting more and more variables of people with different motivations and there is no 'correct' aim. But there are those that harm others and have negative repercussions for our entire species. Self-destruction...awwww yeah!
Wearing different clothes, practicing different religions and cultural habits are fine....up until they become demanding or pressurising on the cultural practices of others. And there are lots of blurring lines in between, where one group said ok and another said "no we're not acceding to that". Add simple bloody-mindedness and hatred to the mix and you've got a nice emotional bomb on your hands. And culture is....more of a notion in patterns of a particular region than anything else, it's the history of the humans in that area, or moving to it. But people forget that those cultural traits they find so immovable, so indestructible, were once either non-existent or have evolved from a different set of cultural traits which may be unrecognisable to the present culture and these are changing...all....the...time. It also gives people an identity, for those who find forging your own an uncomfortable or unwelcome thought.
But people do all kinds of things under the heading of a particular culture or tradition that in fact have little to fuck all to do with that culture or tradition when analysed or examined. It's a big spaghetti-monster mess and that's what we have to untangle.