: The Nazi's weren't Capitalists.
The literature proving the contrary is extensive. My personal recommendation is Franz Neumann's Behemoth. But there are plenty of others right in your local public library...
: But even before the Nazis, the Soviets were liquidating the kulaks in Georgia, to the tune of millions.
The kulaks were incorrigible capitalists, as everyone knows. However, most socialists did not approve of Stalin's reckless policies concerning them---indeed, many died challenging them!
: Where was the external threat then?
The external threat of any country involves the relative strength of the country's internal economy. Use your head.