This all makes sense from a reasoned point of view. But only if you assume western eu leaders have the interests of their populations or even the basic preservation of the nations they lead as even a tertiary concern. But if this was their concern they wouldn't be bankrupting their nations on pet social projects while accepting massive influx of alien cultures that any fool could see is disrupting cohesion in every country doing this.
I really do not want to accept this fact but no other option seems in any way viable:
The people in leadership positions among the establishment of all western nations are psychopaths. I'm not using hyperbole here at all. They really do not care one little bit (and actually seem to despise) for their national traditions or the people that are sustained by them. They've said over and over that national borders are an outdated concept while simultaneously lambasting their native cultures while praising various mud hut peoples.
The reason is simple. These people actually believe they represent the homo novus (new world man etc) and that the survival of their elitist clique is the only thing of any importance whatsoever.
Germany in particular would gladly stick their heads in the sand for eternity avoiding confrontation with Russia, hoping they can get cheap gas forever, Merkel is pretty much the poster child for "strong worded letter" spineless diplomacy. Before Merkel you had Schroeder as long time kraut Chancellor, who after all was one of the fathers of Nord Stream, for which he got kickbacks in the form of a cushy job at Gazprom after he retired from politics.