If the Modernity or Enlightenment Project started fading after 1945, to which religious faith was it most closely aligned to --- and did that religious faith group's power also start to fade in consequence ?
Or perhaps I have it back-asswards.
Was that faith tested in the moral fires of WWII and found seriously failing ?
Such that it never recovered its world-wide culture-wide cachet but became instead ever more tightly clung to by those un-reconciled to the fading of Modernity ?
The world establishment was dominated (pre 1945) by people who were white and male and whose families had originated from North Western Europe and who had been raised in a mainstream Protestant milieu.
Not all that world-wide political-military-economic-intellectual establishment was from that Protestant grouping - think quickly of Hitler, Stalin, Tojo and Mussolini --- but the tone and the pace of Modernity was set by the Protestants.
They dominated the universities, media and civil service, military and business elites (even in countries that had sizeable minorities or majorities of non-Protestants) of most of the biggest most modern nations in the 1940s.
One thinks of 1950s Canada for but one example.
Anglicans, Presbyterians , Methodists, Lutherans.
Some Baptists - maybe.
No Pentacostals or Salvation Army , no orthodox faiths, no Catholics, Jews, Hindus, Buddhists ,etc.
Agnostic or atheist was okay - even expected in certain circles (science) but one still had to have been raised in a Protestant atmosphere before rejecting it for "the higher protestantism" (scientism).