The Republicans would have had a field day with Truman. I'd expect him to lose the next election and who knows how much history would diverge or who the GOP would run. In Asia without China being the bulwark against Communism, perhaps it would with the USSR seek to spread it through the region and drag the US into multiple wars; certainly the US wouldn't have the advantage over the USSR of knowing they had a strong ally threatening the Soviets in case of war in Europe. The 'Evil Empire' as it was was quite restrained in it's foreign policy thanks to the Chinese threat on it's long border, without that and instead an ally there...who knows what they might have gotten up to. Perhaps the USSR would have survived longer without being bankrupted by the major military spending they engaged in to check potential Chinese threats. I also wonder what the global economy would look like with China behind the iron curtain; it is the world's largest economy today, picking up that title in the 1990s, and was a VAST trade partner for the US in the post-war era. I wonder if the Japanese economy would have boomed like it did without the Chinese market? Germany certainly thrived on Chinese trade as well, so I'd think the 'capitalists' would have suffered quite a bit (never mind the Chinese themselves!) without access to the Chinese market and developing economy.