The immigration act was happening regardless of the religious makeup of the country. This was already decided post WWII as the plan for all western countries. It's no surprise almost all White dominant countries passed similar laws in and around the same times.

Maybe so. I don't think it's a surprise either, but that's entangled with the overwhelming domination of the US in the Western sphere.

You may have a point for the Catholic Church (Vatican) having a part to play in multiculturalism worldwide and perhaps the Vatican used its influence to help push these types of laws globally but the Vatican seemed to have supported fascism in Italy and perhaps even supported the Germans. The Vatican has been fighting its own war internally and losing with Vatican II sealing the Catholic Church's fate also. The problem IMO stems more from the money and power of the bankers and their influence in the late 1800s and early 1900s than it has to do with the Catholic Church specifically.

The Vatican played both sides of WWII. There's a reason that some anti-Nazi Catholic partisans are up for sainthood.

To what extent the bankers control the world is a very complex topic. I'm certainly not writing that off, I'm learning in bits and pieces. However, the immense secrecy and power of the RCC cannot be written off either. These are people with their own state and almost no outside scrutiny who are accustomed to world domination, playing strategic games over centuries, and wield influence over more than a billion people.