I think we simply haven't had enough successful proletarian revolutions to get any statistically significant data on the role of religion.

For various reasons Protestantism is mostly associated with northern Europe, which also happens to be solidly imperial core. As a general trend, northern Europeans has been one of the places with the least material pressure to revolt.

Put Norway under brutal foreign colonial rule for a few generations and subject them to crushing exploitation and poverty and you'll see them radicalise just as the Cubans and the Chinese did.

How did Zionism infiltrate American Christianity and sway them away from Socialistic policies?

British theologian John Nelson Darby developed "Dispensationalism" which interpreted biblical prophecies as mandating Jewish return to Palestine before Christ's Second Coming.

This spread throughout the late 19th century (1850-1900) and was published in the 1909 Scofield Reference Bible (a text funded by capitalist backers and disseminated widely in American seminaries).

Figures like Jacob Schiff (Kuhn, Loeb & Co.) and the Rothschilds financed Zionist projects, including early settlements in Palestine. Capitalists purchased religious newspapers or sponsored pro-Zionist content. The Rothschilds and associates influenced outlets like The Fundamentals (1910–1915).

Wealthy Zionists such as Bernard Baruch and Louis Brandeis (a Supreme Court Justice) funded groups like the Federation of American Zionists (1897). They coordinated with clergy to frame Zionism as a moral imperative, leveraging pulpits for political advocacy, such as endorsing the 1917 Balfour Declaration (British government expressing support for the establishment of a "national home for the Jewish people" in Palestine).

Early 20th century Christians were VERY socialist, their voting numbers were growing at an insane rate. They needed to shut that down, and flooded the Church with heavily-capitalist ideology to sway voters towards the establishment (and consequently zionism).

Why does it matter?

CUFI (Christians United For Israel) is much, much larger than AIPAC. They are a 501(c)(3) religious nonprofit, so any donations to Zionist candidates are entirely un-trackable.

The USG want you to be mad at the people "over there" (or to make right-wingers mad at "the jews") and not the people here (who own all of the capital and the government of the people over there).

I hope you're not suggesting that Catholicism has any particular level of compatibility with communism, since the Catholic Church has been an explicitly anticommunist entity for some time now and we can see e.g. in Cuba that Catholicism gets in the way of social reform, which has over and over been accomplished in spite of and by overcoming Catholic prejudices rather than with the support of Catholic teachings.

The empire is protestant, so yes

Hélder Pessoa Câmara OFS (7 February 1909 – 27 August 1999) was a Brazilian Catholic prelate who served as Archbishop of Olinda and Recife from 1964 to 1985 during the military dictatorship in Brazil. He was declared a Servant of God in 2015.

A self-identified socialist, Câmara was an advocate of liberation theology. He did social and political work for the poor and for human rights and democracy during the military regime. Câmara preached for a church closer to the disfavoured people. He is quoted as having said, "When I give food to the poor, they call me a saint. When I ask why they are poor, they call me a communist."

During his first years as a priest he was a supporter of the far-right fascist Brazilian Integralist Action (Ação Integralista Brasileira, AIB), an ideological choice that he later rejected. He was active in the formation of the Brazilian Bishops' Conference (CNBB) in 1952, and served as its first general secretary until 1964. In that role, he founded Caritas Brazil in 1956.

Under the guidance of Câmara, the Catholic Church in Brazil became an outspoken critic of the 1964–1985 military dictatorship, and a powerful movement for social change. In his famous interview with Italian journalist Oriana Fallaci, he also stated that, despite his support for non-violence, he did not condemn violent tactics: "And I respect a lot priests with rifles on their shoulders; I never said that to use weapons against an oppressor is immoral or anti-Christian. But that's not my choice, not my road, not my way to apply the Gospels".

Câmara identified himself as a socialist and not as a Marxist, but while disagreeing with Marxism, had Marxist sympathies. In the Fallaci interview, he stated, "My socialism is special, it's a socialism that respects the human person and goes back to the Gospels. My socialism is justice." He said, concerning Marx, that while he disagreed with his conclusions, he agreed with his analysis of the capitalist society.

He never denied his communist sympathies and he openly supported dialogue with communists. He believed in the Fátima apparitions but he interpreted its call for the "conversion of Russia" as meaning that the Soviet Union and China would abandon their anti-religious policies but will not be rejecting communism.

He wrote: "And what was the appeal of Fatima for? Not for the annihilation of the USSR and China, but for their conversion... In 1967, the Russian Revolution will celebrate its jubilee... We must accelerate the pace, there is no more time to waste".

In a poem dedicated to French Dominican priest Louis-Joseph Lebret, Câmara states his belief that Karl Marx is in Heaven, and has him decorating Lebret of behalf of Jesus Christ.

I mean, capitalism dialectically emerged alongside Protestantism, so it’s not surprising that the most developed capitalist economies might tend towards Protestant, and least in historical backgrounds. Two of those states (UK and Holland) created vast settler colonial empires. I only think this is meaningful in understanding how Protestantism and capitalism emerged together.

I have an inkling of a theory why

Is it the same tired nonsense about how protestantism is uniquely bad as a religion peddled by everyone else with pretenses of radicalism?

Because at this point I may start going back to church out of sheer exasperation with that ridiculous shit.

Not aiming this at op, who presumably has an interesting theory cooking, but ngl I'm getting kinda tired of all these 'left theological' takes. The forces of reaction are currently sweeping across the west, abetted by an alliance of evangelical and catholic orgs and there are still people who want to blame everything on 'calvinism' as if that were useful analysis and not just thinly veiled sectarianism.

There are not that many majority protestant countries to begin with. In most protestant countries. Most protestants share space with Catholicism, eastern-orthodoxy or islam. "Pure-protestant countries" are basically the nordics, some-oceanian countries and collection of countries within southern africa. You have DDR of course that was majority protestant.

If god supported communism he would've given Br*tain to The Levellers

someone should make a Mormon communist country

What about ?

Estonia and Latvia are the exceptions that prove the rule.

But then Lithuania, Poland, and Hungary are proof that a Catholic country that goes communist is just as prone to springing back into fascism as any others.

Grenada is plurality protestant now, but I guess it could have been more catholic back in the commie days?