Irony Served Cold
I agree with the previous poster that no "loss" of China and OTL J Edgar Hoover being brought to heel or falling down a well would've done wonders for defusing the Red Scare of the 1950's in the US.
If we could have paid attention to the facts on the ground in and done a sane threat assessment of China and Vietnam, we would not have snubbed the PRC or Ho Chi Minh.
We had OSS contacts during WWII with Ho Chi Minh and the Communist Chinese, and HCM dearly hoped the US would recognize his regime in Indochina, because the US had never made any bones about owning the place. France did and had something to prove.
The US could have made decolonization contingent on getting Marshall Plan aid, but they didn't, because they had plans for Europe (France, the UK, the Netherlands, et al) being the bulwark against Communism.
As to Cold War dictators getting boatloads of US cash, military/CIA support, and so forth, we just took our Latin American policy of interventionism and setting up pliable caudillos global.
If they threatened US interests (mainly profits), we removed them, democratically elected or not. Guatemala, Chile, Zaire, Iran, Iraq, and Panama can all attest to that.
So, for US Cold War policy to have been more humane, less anti-democratic, and so forth, you gotta butterfly away Manifest Destiny, the Monroe Doctrine and our unique sense of Puritan imperialism for our opponent-of-the-moment's own good before WW II.
After WWII, have somebody less flinty and insecure than Truman in charge, eager to strike out on his own from FDR's willingness to work with anyone to defeat the main enemy, Hitler.
We've tossed around the idea of Wilkie or somebody else taking over for FDR who is less confrontational with the Soviets on the board, but IMNSHO, the main POD would be somebody who values self-determination and looks down the road for long-term economic and political gains working with folks with secure power bases that don't need boatloads of American "help". However, it would most likely take until the 1960's for us to get out of the Lend-lease/ "arsenal of democracy" mindset, barring some isolationist volte face in 1948.
IOW, damned near ASB for the US to have done better.