Question

In what country did a civil war in 1946 contribute to tensions between the soviet union and great britain?

Answer 1

Greece and China both had civil wars at this time.

They were both fought before the end of the Second Great war and both were vicious accounting for many deaths.

I think that the answer you want is Greece. It effectively went on for 10 years -- throughout the 1940s. It was the last hurrah of the British Empire trying to influence countries beyond its borders.