Diversity inhibits its own opposition.
For background, read this.
Putnam's work on diversity revealed that increasing diversity not only lowered levels of between-group trust, but also decreased the levels of trust between individuals of the same group.
If one considers that it is precisely collective group action that is a necessary component of a group's resistance to the corrosive effects of diversity and multiculturalism, then one observes that diversity has the ability to disarm its own opposition.
One can consider a majority ethny subjected to increasing levels of diversity within their nation-state. This diversity directly damages the interest of the native, majority ethny through negative effects on ultimate interests (e.g., EGI decreased through race replacement immigration, differential birthrates, and miscegenation) as well as important proximate interests (socioeconomic, political, cultural, etc. displacement, as well as legal and illegal acts of aggression by the newcomers against the natives).
The long term interests of this endangered native ethny will require an organized resistance to diversity. This organized resistance will require collective action, a sense of group identity, and must be proofed against excessive free riding. All of this requires reasonably high levels of trust between group members. But the very diversity they wish to oppose erodes inter-group trust and makes a more collectivist mindset ever more difficult to create and maintain. Instead, diversity would tend to promote atomized individualism, derived from a sense of mistrust and alienation ("bowling alone"), that would sap the strength of any organized resistance movement.
While this process of group disarmament could in theory occur in any group subjected to diversity, it would have the most harmful effects on groups already relatively high on individualism and low on collectivism. A very collectivist group may well be more resistant to the ingroup mistrust promoted by diversity, and even if diversity caused this group to move in the individualist direction, if they had started high on the collectivist scale, they may be able to maintain a sufficient level of collective group action to protect themselves and their interests.
On the other hand, a group already individualist, with weaker abilities to engage in collective action, such a group would be pushed into pathologically radical atomized individualism by diversity, and lose whatever ability for collective action they had previously possessed. Europeans are relatively low on collectivism, while being high on individualism, and are thus exquisitely vulnerable to the effects of diversity on ingroup mistrust. Jews and Asians, being more collectivist, would be far more resistant to diversity; even if they were to move toward a more individualist direction, they may still fall within a "safe" range that maintains the ability for group collective action.
For example, imagine a 0-100 scale, with 0 being maximum individualism, and 100 being maximum collectivism. Imagine that the position of different groups on this scale is fixed within a range, by both genes and deeply ingrained cultural and historical influences. A group may have some ability to move around within their range, based on circumstances, becoming a bit more collectivist under threat and a bit more individualist during times of peace and plenty (the magnitude of these shifts may also vary between groups, but we need not concern ourselves with this detail here).
Let's say that the threshold for collective action is at a rating of 50 or greater. Europeans may fall within the 30-55 range, with the 30-45 range being the default position, and levels of collectivism of 45-55 observed in times of stress (as a historical example, National Socialist collective organizing of the German people against Jews and other enemies). Jews and Asians would be, normally, in the 65-90 range. If diversity causes a 10 point slide toward individualism, then Europeans would have their ability for collective action eliminated (they would now have a 20-45 range), while Jews and Asians, now in the 55-80 range, would still maintain the ability to act collectively.
Of course, these numbers are merely for the sake of illustration and are not meant to represent any objective, quantitative reality. Nevertheless, the point is clear. Given that it is the White world that is predominantly subjected to increasing diversity, and that is are Whites who are, generally speaking, skewed toward individualism, it is obvious that diversity is a potent memetic-biological weapon in the war to destroy the White world.
This is a large hurdle to overcome. Enhancing inter-group trust through honorable and ethical behavior, should be a "must" for the "movement" - but I see little evidence of this actually occurring. This underscores why "free-riding" (from everything from politics to vaccination) is so deadly; if one sees others taking advantage of the group's collective social goods while making no contribution to those goods themselves, this will further erode ingroup trust and make further collective action impossible.
We need to understand our place on the individualism-collectivism continuum, also understand the need for collective action, and further understand the pernicious effects of diversity. To not do so is folly and will lead inevitably to our final defeat.