Initial concern following WW2? There was the Great Red Scare just after WW1, for heaven’s sake. The Russian Revolutions had just happened, the Czar was dead, and the Russian Empire was morphing into the Union of Soviet Socialist Republics, had dropped out of the war, and had sued for peace.
And there’d been a lot of socialist agitation before WW1. The Haymarket Affair happened in the 1880s. The disadvantages of centralized planning hadn’t become apparent, and it wasn’t until the later 1920s that holes started to appear in the USSR’s image as a brave new revolutionary world.
For a non-communist, but still socialist, view of things, read HG Wells’ later works, suich as The Shape of Things to Come and The World Set Free. Here we have works written in the 1930s speaking of the collapes of the capalist order due to wars and overextension, and a new ‘Modern State’ society springing up amidst the decay.
But if you look at what happened, the Communist rebellions happened in poorer countires and areas, ones without an inclusive social tradition, or where people were starving, and had nothing to lose by rebelling.
The US and its allies would have been better off supporting policies that benefitted the people who would otherwise rebel. And they did to some degree–look at what the Marshall Plan did for Europe.
But they should have extended that to SE Asia and South America and Central America and all the other places, sat down with all those dictators, and said, “Look. We don’t care what you call yourselves. We do care that the people aren’t being treated fairly. We won’t support you if you don’t treat your own people well.” Instead, too often they seemed to say, “You’re anti-Communist? Great! We’ll support you, no matter what you do, if you help us oppose the Russians.”
So I don’t think the US overreacted, but it definitely didn’t react in the most efficient dirrection.