straykat:
I think a lot more happened in Vatican II than liturgical change. The ecumenism (even with non Christians) was unthinkable before. At the highest levels, where even the Pope (now St. JP II) presided over some of it.
If it was unthinkable, how did Kennedy get elected? That was November 1960. Vatican II opened in Oct. 1962.
I think a great deal more societal change, including changes among Catholics, came about because of World War I and especially World War II–the cooperation between groups that were separate before to fight a unified fight, the loss of faith and damage to the family due to the atrocities seen by and probably the widespread and untreated PTSD suffered by the veterans, especially the youngest ones, the period of prosperity that went with it, and so on. (Europe, meanwhile, has much more societal devastation to work through, of course!!)
Those world wars did far more damage than many give them credit for. Had they not happened, there is a good chance the societal upheaval that lead Pope John XXIII to conclude Vatican II was needed may have been absent or very different. (It is also difficult to say what would have happened in the world if World War II had not. It depends so much on what would have replaced it, which is of course impossible to say…)