There's been a few related questions to this in the past, but none that have answered it from the particular angle I'm looking at.

I understand that, on paper, the ROC was one of the major Allies and ended up victorious, etc. But geopolitically, the ROC was far, far behind the others at the time, with an ongoing civil war, factionalism, very little industry, very little ability to project power militarily, and so on. What was the pragmatic motivation for giving China, as it existed then, such a prominent and powerful role in the UN?