[varjag]

> Even the most small details of the Second World War are now mostly declassified, and so we can see individual contributions in the context of that war and all wars proceeding it.

We shouldn't extrapolate the customs of democratic societies to the rest of the world. The bulk of Soviet WW2 archives are to remain classified in Russia until at least 2040.

[DCoder]

Moreover, some archives were destroyed a) to prevent them from being captured during the war, especially in the 1941 defense of Moscow, and b) to cover up whatever the leaders considered too sensitive later. This second portion also includes docs relating to post-WW2 events like the Totskoye nuclear exercise [0], destroyed decades after the fact because "the archives ran out of space".

[0]: https://en.wikipedia.org/wiki/Totskoye_nuclear_exercise