The Chinese didn't need anyone to pour funds into their country; they did it with their work and intelligence, and this after Mao left nothing but ruins.

Sorry, but I have to call you out on this. China from 1900 ~ 2000 was suppose to be all brains? No. They absolutely got help from Germany, where even Hitler at one point wanted to make China their ally but funnily enough, even with Germany's help, they were getting destroyed by their neighbor Japan which ultimately lead to Germany switching partners. https://en.wikipedia.org/wiki/Sino-German_cooperation_(1926%E2%80%931941)

Mao Zedong, THE COMMUNIST, didn't just operate alone. He had big time help from the Soviet Union who provided him millions in loans. https://en.wikipedia.org/wiki/Sino-Soviet_Treaty_of_Friendship,_Alliance_and_Mutual_Assistance

The Japanese saw their country completely devastated by nuclear bombs.

Yeah they did, but you deliberately ignored America was not interested in letting Japan rot after the war. Just like West Germany, it was part of the post WW2 agenda to have another ally against the Soviets. https://history.state.gov/milestones/1945-1952/japan-reconstruction

In the meantime, South Africa regresses back to third world and the thought of Africans creating a new civilization doesn't sound too plausible to me.

Modern South Africa still has a higher GDP per capita vs the end of Apartheid. They're actually more rich, despite their government being corrupt. But it's just one African country, which is really bizarre to judge an entire continent. Like I said in the last thread, imagine using Ukraine to describe all of Europe? It's just not scientific... The past decade has actually shown African countries are beginning to undertake some more ambitious projects. Ethiopia has already met their goal of constructing a new hydroelectric dam. Rwanda has also seriously stepped up its urbanization efforts (which is important, since city's play an important role in driving economic growth). https://www.designindaba.com/articles/point-view/planning-impossible

The concept of isolationism didn't come out of nowhere. These nations had good cause to prefer it,

And they paid the ultimate price for it when European powers marched inside their borders and basically stole territory from them. China wouldn't regain control of Hong Kong until what? 1997? And that was after they were forced to sign a humiliating contract that let the British own it for 99 years. These countries are always free to go back to being isolationist again. But they can enjoy sitting next to North Korea and completely stagnating.

These nations had good cause to prefer it, but obviously American and British intervention denied them this right.

This sounds like a defense of the current third world situation. The British and USA are still screwing with them to this day with foreign intervention. It's more important these countries catch up economically so they can reassert their sovereignty.