ΔE 6.5, close: similar, with a visible difference side by side. US Dark Green is more muted, cooler than Dark Soviet Khaki.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). US Dark Green is more muted, cooler than Dark Soviet Khaki.
The same difference applies the other way round: Dark Soviet Khaki is more saturated, warmer.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Dark Soviet Khaki on the colour wheel See US Dark Green on the colour wheel
All matches: Dark Soviet Khaki equivalents · US Dark Green equivalents